Welcome to the modding community
get them to be built in a new shop
So my question to you is; are you trying to get them built in a custom workshop of your own? This would require you to create a custom workshop and a custom reaction. Or do you just want them to be craft able in say, the clothier's workshop? In context it seems like you are trying just to get them to be craft able in any workshop like a normal piece of clothing. If this is incorrect let me know and I can help you.
Basically races (also known as "entities")are allowed to have race exclusive items, such as how humans have pikes and elves have bows. So in addition to creating the item -which you have done-, you also need to tell the entities that they are allowed to use the item.
- Open up your entity_default.txt file in the raws folder.**
- ctrl +f and search for 'shoes'
- you should see other things around it like ARMOR PANTS GLOVES and the like
- simply copy one of the SHOES:#:COMMON tags and replace # with the item name that you created in this case:
[SHOES:ITEM_SHOES_BOOTS_NEW:COMMON]
Also, to note brackets are important and the code you posted is missing some brackets. The first line should be
[ITEM_SHOES:ITEM_SHOES_BOOTS_NEW]
** entity default has a list of all the available races in the game, if you wanted humans to use this article of clothing you will have to look for the human entity (ENTITY:PLAINS) however since the dwarven entity is the first entity on the list searching should get you into the right spot.