docs: Update metric job docs with some of the available config options

[meeech]

Was trying to run metric jobs in a different namespace. Wasn't documented how to do that. Now it is.

Checklist:

• Either (a) I've created an enhancement proposal and discussed it with the community, (b) this is a bug fix, or (c) this is a chore.
• The title of the PR is (a) conventional with a list of types and scopes found here, (b) states what changed, and (c) suffixes the related issues number. E.g. "fix(controller): Updates such and such. Fixes #1234".
• I've signed my commits with DCO
• I have written unit and/or e2e tests for my change. PRs without these are unlikely to be merged.
• My builds are green. Try syncing with master if they are not.
• My organization is added to USERS.md.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[github-actions]

Published E2E Test Results

  4 files    4 suites   3h 12m 55s ⏱️
113 tests 104 ✅  7 💤 2 ❌
454 runs  424 ✅ 28 💤 2 ❌

For more details on these failures, see this check.

Results for commit ce44a7b.

[github-actions]

Published Unit Test Results

2 275 tests   2 275 ✅  2m 58s ⏱️
  128 suites      0 💤
    1 files        0 ❌

Results for commit ce44a7b.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 83.90%. Comparing base (00e39b1) to head (ce44a7b).
Report is 76 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3839      +/-   ##
==========================================
+ Coverage   83.89%   83.90%   +0.01%     
==========================================
  Files         163      163              
  Lines       18560    18560              
==========================================
+ Hits        15571    15573       +2     
+ Misses       2118     2117       -1     
+ Partials      871      870       -1     

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