src: add a top-level Development section

and add explicit links to the main repository on sr.ht
also add link to the GitHub mirror.

deploy: optionally generate a specific tag for /x/tex vanity imports

index: add link to mailing list web interface

all: streamline deploy target

news/release-0.3.0: add a dvi.Program example

news/release-0.3.0: fix up official release date

all: updates and polish, add v0.{2,3}.0 releases

all: add star-tex.org/x/ redirects

Signed-off-by: Sebastien Binet <s@sbinet.org>

all: first import

Signed-off-by: Sebastien Binet <s@sbinet.org>