Fix Markdown syntax for preprocessing docs page

[dinakazemi]

• Closes Fix “preprocessing” docs page #3360
• Tests included or not required because: re-generated docs and checked that the new documentation has the correct link

• Release notes not necessary because: I think this should be part of the 1.10.5 release, but could not see an associated md file for this release

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 76.67%. Comparing base (09c88b1) to head (4758eb8).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3418      +/-   ##
==========================================
+ Coverage   76.65%   76.67%   +0.01%     
==========================================
  Files         112      112              
  Lines       12946    12946              
==========================================
+ Hits         9924     9926       +2     
+ Misses       3022     3020       -2     

see 1 file with indirect coverage changes

[dinakazemi]

Hi scanpy developers,
I wasn't sure if this change should be included as part of a milestone or not (hence the failing validation check). Could you confirm if this should be included as part of the 1.10.5 release? If so, how can I add the milestone and if not, how can I add the no-milestone label?
Thanks!

[flying-sheep]

Hi! Thanks for the contribution! We’re in the process of releasing 1.11.0, and won’t make a 1.10.5 release anymore.

I added a release note using our new process documented here: https://scanpy.readthedocs.io/en/latest/dev/documentation.html#adding-to-the-docs

We should link to that page from our “making a PR” docs!