~25 typo fixes, updated DJ station instruction sheet, replaced missing disposal pipe underneath HoP office door

* Edited encryptionkey.dm: Fixes about nineteen typos
* Edited tools.dm: Fixes "screwwy" typo in screwdriver description
* Edited paper.dm: Updates DJ station instruction sheet in light of the removal of the broadcaster and receiver from the DJ station
* Edited lib_items.dm: Fixes typo in "unwrenched" in a bookshelf deconstruction step
* Edited tgstation.2.1.2.dmm: Adds updated DJ station sheet to DJ station, replaces missing disposal pipe underneath HoP office door.
* Edited utility_closets.dm: Fixed oxygen closet description
* Edited DJ station paper to read better

Holy shit I wish there was an easier way to update existing commits without making more of them.