Remove DEPLOYING.md

This (internal) document is outdated to an extent that makes it advisable
to remove it altogether
Add lilyglyphs_private/pdfs dir

It was overlooked to add this .forcedir file when extracting the archive again
(see 1d0de5dcf8baaa4027ded96f474a64899e9b1145)
Update INSTALL: Prepare for CTAN upload

Describe the different installation options
README: Add reference to openlilylib-user
lilyglyphs.sty: 'Cosmetic' clean-up
Add README with info about the main folders

Tell what the folders are about
Rename py folder to scripts

This is more in line with the TDS structure
Rename advertisement/overview to 'example'
documentation: Move helper files to 'resources'
Move glyphlist to documentation folder

It is now in the top level of documentation.
Resources have been moved to the resources folder
Rename otf directory to fonts