Small fixes in git_workflow guide

[Molkree]

Description

Just some typo fixes and updated GitHub links from HTTP to HTTPS.

Motivation and Context

Typos are self-explanatory, HTTPS saves your browser one redirect.

How Has This Been Tested?

• Testing pipeline
• Reference Data Comparison following these instructions
• I have built docs locally, looks fine.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• None of the above (please describe)

Checklist:

• My code follows the code style of this project
• My change requires a change to the documentation
• I have updated the documentation accordingly
• I have built the documentation on my fork following these instructions
• I have assigned and requested two reviewers for this pull request

[codecov]

Codecov Report

Merging #1530 (db39ecf) into master (09f992f) will not change coverage.
The diff coverage is n/a.

❗ Current head db39ecf differs from pull request most recent head d8e519d. Consider uploading reports for the commit d8e519d to get more accurate results

@@           Coverage Diff           @@
##           master    #1530   +/-   ##
=======================================
  Coverage   67.57%   67.57%           
=======================================
  Files          68       68           
  Lines        6100     6100           
=======================================
  Hits         4122     4122           
  Misses       1978     1978           

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[Molkree]

"The editing workflow" section suggests building docs with python setup.py build_sphinx however Documentation guidelines suggest to build with python setup.py build_docs or make html.
Is the latter preferred now?