Download mdtoc directly

[saschagrunert]

What type of PR is this?

/kind documentation

What this PR does / why we need it:

Download the binary directly and add a toc to the README.md.

Which issue(s) this PR fixes:

None

Does this PR have test?

None

Special notes for your reviewer:

None

Does this PR introduce a user-facing change?

None

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 42.06%. Comparing base (11d77f4) to head (21f7fd0).
Report is 346 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2354      +/-   ##
==========================================
- Coverage   45.50%   42.06%   -3.44%     
==========================================
  Files          79      109      +30     
  Lines        7782    15863    +8081     
==========================================
+ Hits         3541     6673    +3132     
- Misses       4099     8696    +4597     
- Partials      142      494     +352     

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: ccojocar, saschagrunert

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [ccojocar,saschagrunert]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment