THANKS: cleanup duplicates

THANKS: contributors from the 8.10.1 release

THANKS: contributors from 8.10.0

THANKS: add names from the 8.9.1 release notes

Also remove duplicates

THANKS: updates from the 8.9.0 release

THANKS: add contributors from 8.8.0

THANKS: new contributors from the 8.7.0 release

THANKS: add bug reporter from #740

Ref: https://github.com/curl/curl/issues/740

THANKS: add Dmitry Tretyakov

... since I missed to give credit to the report in the fix of #12861

THANKS: new contributors from 8.5.0

THANKS: add Alexander Bartel and Brennan Kinney

They reported and investigated #10259 which was fixed by 7b2d98df.

Ref: https://github.com/curl/curl/issues/10259

cmake: use curldown to build man pages

This throws away the previous HTML and PDF producers, to mimic what
Makefile.am does as faithfully as possible.

Closes #12753

RELEASE-NOTES: synced

The curl 8.5.0 release.

THANKS: add contributors from 8.4.0

THANKS: add Eric Murphy

He reported #11850 (quiche build error) but I forgot to add a
'reported-by' entry in the fix 267e14f1.

THANKS: contributors from 8.3.0

THANKS: add contributors from 8.2.1

THANKS: add contributors from 8.2.0

THANKS: contributors from 8.1.2

THANKS: contributors from the 8.1.1 release

THANKS: contributors from the 8.1.0 release

THANKS: from the 8.0.0 release

THANKS: add contributors from 7.88.1

THANKS: added contributors from 7.88.0

THANKS: 40 new contributors from 7.87.0