Updated Docs

i noticed a couple of times that the commands in the docs aren't always linked to the description of each command, hence i went through all the command to link them properly. as with previous procedure, i didn't not link a command within the description of the same.

as a side product, i also created this Alphabetic list of NSIS commands, which might become handy in one or the other case.

..and here's what has changed

alright, kichik told me the docs are generated from .but files. i'm already on overworking these!

Nice job, thanks!