Lightweight subscription to Gemini pages

[Solderpunk]

Howdy Geminauts,

As per recent discussions, I have now published a "companion
specification" for lightweight subscription to Gemini pages which do not
have Atom feeds.  Please see:

gemini://gemini.circumlunar.space/docs/companion/subscription.gmi

I ended up wording some things slightly differently from my earlier
proposal.  Link items now represent feed entires if the first 10
characters of their label match the YYYY-MM-DD format, and their title
is derived from everything after the first whitespace-separated
component (with mention that implementations may clean up separating
hyphens, etc.).  This is slightly more flexible and means that all of
the following label formats will be recognised as entries:

2020-11-22: A post title
2020-11-22  A post title
2020-11-22 - A post title
2020-11-22T17:45:20: A post title
2020-11-22T17:45:20 A post title
2020-11-22T17:45:20 - A post title

Note that the timestamps in the latter three formats will not be
interpreted according to this specification, but since I have actually
seen at least one use of full-blown ISO 8601 timestamps in the wild
it seemed wise to permit them to be recognised as entries.  I don't
expect or encourage people to adopt this style as it results in ugly
pages from the perspective of human readers.

Cheers,
Solderpunk