Fixes grammar errors in clothing items

I already made a pull for this, but GitHub fought tooth and nail to prevent me from doing it right, so here's a re-upload. Copied from the previous PR:

I have always been tired of grammar errors like missing punctuation or improper capitalization in items, so I decided to do something about it.

In short:
1. Grammar errors in all articles of clothing have been corrected (i.e. greatcoat lacking punctuation)
2. Descriptions have been edited or added for some pieces of clothing (i.e. science goggles and grey jumpsuit)

I will be making more PRs in the future to fix errors in other items.
if we're gonna be really pedantic, why's collectable capitalised?