Move "All Packages" link above categories and recently modified in the index.

See merge request !1

from the excel spreadsheet. The list of labels to be removed is held in the INDEX_FILE
(home.md) as an html comment with the first entry of INVISIBLE_LABEL_SET followed
by a list of labels to be excluded.

filenames. This is to mitigate the proliferation of categories based on capitalisation,
e.g. Application and application ending up as two separate categories. It tries to preserve
the capitalisation of the names for display purposes to users e.g. DOE doesn't get presented
as doe.

html comment strings in the home.md page