Update documentation

[javierdelapuente]

last version

Overview

Update documentation so:

• The examples for the new interface for database are working: Use the new database interface for the postgresql relation #79
• run-action -> run as it is the new syntax for juju 3.
• Use the latest/edge channel of Redis, as stable does not work.

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 - Manging 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)

[github-actions]

Test coverage for 38628ec

Name              Stmts   Miss Branch BrPart  Cover   Missing
-------------------------------------------------------------
src/charm.py        335     31     80     12    90%   186, 194-195, 207, 335->343, 376->381, 580-582, 587-588, 599-601, 606-607, 619-621, 626-627, 639-641, 666-668, 710->exit, 720->exit, 750-756, 782->exit, 796-797, 807->exit, 821
src/database.py      30      1      8      1    95%   56
-------------------------------------------------------------
TOTAL               365     32     88     13    90%

Static code analysis report

Run started:2024-04-10 11:38:51.958998

Test results:
  No issues identified.

Code scanned:
  Total lines of code: 1984
  Total lines skipped (#nosec): 3
  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):