docs: improved pr generator doc to include screenshot for configuring URL

[rishabh625]

Signed-off-by: rishabh625 rishabhmishra625@gmail.com

Note on DCO:

If the DCO action in the integration test fails, one or more of your commits are not signed off. Please click on the Details link next to the DCO action for instructions on how to resolve this.

Checklist:

• Either (a) I've created an enhancement proposal and discussed it with the community, (b) this is a bug fix, or (c) this does not need to be in the release notes.
• The title of the PR states what changed and the related issues number (used for the release note).
• I've included "Closes [ISSUE #]" or "Fixes [ISSUE #]" in the description to automatically close the associated issue.
• I've updated both the CLI and UI to expose my feature, or I plan to submit a second PR with them.
• Does this PR require documentation updates?
• I've updated documentation as required by this PR.
• Optional. My organization is added to USERS.md.
• I have signed off all my commits as required by DCO
• I have written unit and/or e2e tests for my change. PRs without these are unlikely to be merged.
• My build is green (troubleshooting builds).

i didn't notice content-type setting while configuring for webhook, and wasted lot of time, this doc update could help by pointing exactly

[rishabh625]

@crenshaw-dev : Can u please review this.

[codecov]

Codecov Report

Merging #9350 (3325337) into master (b587e0c) will increase coverage by 0.11%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #9350      +/-   ##
==========================================
+ Coverage   46.06%   46.17%   +0.11%     
==========================================
  Files         217      218       +1     
  Lines       25908    25917       +9     
==========================================
+ Hits        11934    11967      +33     
+ Misses      12317    12294      -23     
+ Partials     1657     1656       -1     

Impacted Files	Coverage Δ
applicationset/services/scm_provider/github.go	75.29% <0.00%> (-5.89%)	⬇️
server/server.go	54.12% <0.00%> (-0.11%)	⬇️
cmd/argocd/commands/app_actions.go	0.00% <0.00%> (ø)
cmd/argocd/commands/app_resources.go	8.54% <0.00%> (ø)
util/settings/settings.go	48.16% <0.00%> (+0.05%)	⬆️
cmd/util/app.go	52.38% <0.00%> (+1.97%)	⬆️
cmd/argocd/commands/app.go	20.14% <0.00%> (+2.15%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update b587e0c...3325337. Read the comment docs.

[crenshaw-dev]

lgtm, thanks!