[crmsh-4.6] Dev: doc/website-v1: add man-4.6 (#1374)

[nicholasyang2022]

and related tools and Makefile.

Also update related scripts from python 2.x to python 3.x.

Usage:

$ cd doc/toolchain
$ podman build -t local/crmsh-doc-builder .
$ cd ..
$ make clean
$ podman run --rm -ti -v ..:/opt/crmsh local/crmsh-doc-builder:latest make website
$ podman run --rm -ti -p 2080:80 -v $(readlink -f website-v1/gen):/usr/share/nginx/html docker.io/nginx

Part of #1374.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 52.84%. Comparing base (bfd7f06) to head (a369f9c).

Additional details and impacted files

@@            Coverage Diff             @@
##           crmsh-4.6    #1383   +/-   ##
==========================================
  Coverage      52.83%   52.84%           
==========================================
  Files             79       79           
  Lines          23949    23949           
==========================================
+ Hits           12654    12655    +1     
+ Misses         11295    11294    -1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[liangxin1300]

Some same commits with #1380? I've approved it, you can merge

[liangxin1300]

In this PR, could you also update what you've changed and introduce the new process for the website update part in https://github.com/ClusterLabs/crmsh/blob/master/doc/releasing-a-new-version.md?

Thanks!