Add-on Features
1. Medieval workshop
-The first thing you should craft is the medieval crafting table or workshop, because in its inventory you can make everything related to this add-on. 
You can create the medieval workshop on the normal crafting table.
Type: block-crafting table.
Items needed for crafting: Planks, raw iron, raw copper
Crafting place: Normal crafting table.

2. Straw.
This item will help you to craft important parts of some machines.
Type: Item.
Other uses: furnace fuel, each one burns 4 items.
crafting place: Medieval workshop
Items needed for crafting: Wheat and sticks

3. Beam
It is an important item to make some rustic machines.
Other uses: furnace fuel, each one burns 10 items.
Crafting place: Medieval workshop
Items needed for crafting: Logs.

4. Wheel
Item necessary for the manufacture of moving machines
Other uses: furnace fuel, each one burns 8 items.
Crafting place: Medieval workshop
Items needed for crafting: Straw and sticks.

Many of the following entities need to be tamed with a log, so that the owner can access their inventory and gain experience from the mobs destroyed by them. None of these entities have fall damage.

5. Plow
Rustic machine that you can use to till the land, and turn it into farmland.
It works in 3x3 block areas, and you can ride it. It will automatically till blocks of grass and dirt that are under it. 
Crafting place: Medieval workshop
Items needed for crafting: Sticks, planks, iron ingot, wheel.
Tameable with: log.
Healable with: stick
It has a private inventory that can only be used by its owner
Command to have its spawn egg [for operators]: /give @s se:arado_spawn_egg 1
Command to summon this entity [for operators]: /summon se:arado ~ ~ ~

6. Ballista
It is a static turret-type entity that defends the area where you place it within a radius of 15 blocks. It shoots normal arrows and does not need you to reload it.
Crafting place: Medieval workshop
Items needed for crafting: Arrow, beams, wheels.
Tameable with: log.
Healable with: stick
It has a private inventory that can only be used by its owner.
Command to have its spawn egg [for operators]: /give @s se:ballista_spawn_egg 1
Command to summon this entity [for operators]: /summon se:ballista ~ ~ ~

7. Battering ram.
It is a very useful machine to open a path and get many resources, it destroys most of the blocks near it, for this reason, you can use it to build underground mines and find many ores.
It cannot dig down, so you should spawn it at the height you require. You can ride it and has 4 sites.
Crafting place: Medieval workshop
Items needed for crafting: Straw, beams, wheels.
Tameable with: log.
Healable with: stick
It has a private inventory that can only be used by its owner.
Command to have its spawn egg [for operators]: /give @s se:bram_spawn_egg 1
Command to summon this entity [for operators]: /summon se:bram ~ ~ ~

8. Harvester.
It allows you to collect the ripe crops ready to harvest, you can ride it while it does its job. Also, keep harvested items in its inventory.
Crafting place: Medieval workshop
Items needed for crafting: Planks, sticks, wheels.
Tameable with: log.
Healable with: stick
It has a private inventory that can only be used by its owner.
Command to have its spawn egg [for operators]: /give @s se:cose_spawn_egg 1
Command to summon this entity [for operators]: /summon se:cose ~ ~ ~

9. Scythe
It is a transport and protection entity, it generates an area damage that affects any hostile mob in its nearby area. You can ride it.
Crafting place: Medieval workshop
Items needed for crafting: Iron ingots, beam, wheels.
Tameable with: log.
Healable with: stick
It has a private inventory that can only be used by its owner.
Command to have its spawn egg [for operators]: /give @s se:guada_spawn_egg 1
Command to summon this entity [for operators]: /summon se:guada ~ ~ ~

10. Wall of spikes
It is an entity and not a block, which deals damage by wither effect to any hostile mob that touches it.
Crafting place: Medieval workshop
Items needed for crafting: Straw, beams.
Tameable with: log.
Healable with: stick
Command to have its spawn egg [for operators]: /give @s se:poste_spawn_egg 1
Command to summon this entity [for operators]: /summon se:poste ~ ~ ~

Farm.
The following items help you to multiply the seeds needed to get more crops. With only 8 seeds of each crop, and by manufacturing them together with the garden shovel, you get 8 times more seeds to sow, in total a stack of 64 seeds.
 

11. Garden shovel.
Important item to craft all farming tools.
Items needed for crafting: Stick and cobblestone.

12. PBamboo.
To sow: Bamboo.
Items needed for crafting: Garden shovel and bamboo.
You get: PBamboo x64

13. PBeetroot.
To sow: Beetroot.
Items needed for crafting: Garden shovel and beetroot seeds.
You get: PBeetroot x64
 

14. PCarrot.
To sow: Carrot.
Items needed for crafting: Garden shovel and carrots.
You get: PCarrot x64

15. PKelp.
To sow: Kelp.
Items needed for crafting: Garden shovel and kelp.
You get: PKelp x64.

16. PPotato.
To sow: Potato.
Items needed for crafting: Garden shovel and potato.
You get: PPotato x64.

17. PPump.
To sow: Pumpkin.
Items needed for crafting: Garden shovel and pumpkin seeds.
You get: PPump x64.

18. PSugar.
To sow: Sugar cane.
Items needed for crafting: Garden shovel and reeds.
You get: PSugar x64.

19. PWart.
To sow: Nether wart.
Items needed for crafting: Garden shovel and nether wart.
You get: PWart x64.

20. PWheat.
To sow: Wheat.
Items needed for crafting: Garden shovel and wheat seeds.
You get: PWheat x64.

21. PWmelon.
To sow: Melon.
Items needed for crafting: Garden shovel and melon seeds.
You get: PWmelon x64.

22. Worm block.
It allows to recycle some items of plants, to obtain bone meal.
Items needed for crafting: Trapdoor and dirt.
From the inventory of the worm block you can obtain 4 items of bone meal from 1 item of: Dirt, bamboo, beetroot, beetroot seeds, carrot, kelp, potato, pumpkin block, pumpkin seeds, reed, wart, wheat, wheat seeds, melon or melon seeds.
 

Licenses:

– You are allowed to make videos or pictures with my add-on (YouTube, Twitch, etc).
– You are not allowed to modify my add-on.
– Don’t ask me for permissions. You are not allowed to claim my add-on as your own! 
– You are not allowed to redistribute and/or reupload it
– If you like to share my add-on, please share it with a link to MY LINK
– If you modified something or use my add-on, please leave a note.
Please consider my agreement.

Thank you for your polite and constructive suggestions, I will try to improve. 
Greetings and thanks for the visit.