Standardise and improve Jenkins tutorial

[javierdelapuente]

Applicable spec:

Overview

Standarise the Jenkins tutorial with other tutorials and improve/fix the tutorial.

Rationale

Juju Events Changes

Module Changes

Library Changes

Checklist

• The charm style guide was applied
• The contributing guide was applied
• The changes are compliant with ISD054 - Managing Charm Complexity
• The documentation is generated using src-docs
• The documentation for charmhub is updated.
• The PR is tagged with appropriate label (urgent, trivial, complex)

[erinecon]

Excellent draft! I added some nitpick comments. Thanks for your work on this tutorial :)

[github-actions]

Test coverage for c5c03a4

Name                Stmts   Miss Branch BrPart  Cover   Missing
---------------------------------------------------------------
src/actions.py         29      0      4      0   100%
src/agent.py          119      0     20      0   100%
src/auth_proxy.py      52      0      8      0   100%
src/charm.py           89      0     14      0   100%
src/cos.py             20      0      0      0   100%
src/ingress.py         16      0      4      0   100%
src/jenkins.py        376      0     60      0   100%
src/pebble.py          25      0      2      0   100%
src/state.py          109      0     24      0   100%
src/timerange.py       30      0      6      0   100%
---------------------------------------------------------------
TOTAL                 865      0    142      0   100%

Static code analysis report

Run started:2024-10-01 13:06:28.123975

Test results:
  No issues identified.

Code scanned:
  Total lines of code: 7513
  Total lines skipped (#nosec): 6
  Total potential issues skipped due to specifically being disabled (e.g., #nosec BXXX): 0

Run metrics:
  Total issues (by severity):
  	Undefined: 0
  	Low: 0
  	Medium: 0
  	High: 0
  Total issues (by confidence):
  	Undefined: 0
  	Low: 0
  	Medium: 0
  	High: 0
Files skipped (0):

[erinecon]

The tutorial looks great -- thank you for your time and effort :)

I approve of the documentation changes 👍
(Didn't officially approve since other files were changed in this PR) the other files are NOT related to prod code, will approve now