Add changelog inside the application

[djaiss]

This PR adds a "What's new" section inside the product, so users can discover the new features as we introduce them.

Code-related tasks

• Tests added for this feature/bug.
• Impact on the seeders.
• Impact on the API.

If the code changes the SQL schema

• Impact on account export.
• Impact on importing data with vCard and .csv files.
• Impact on account reset and deletion.

Other tasks

• CHANGELOG entry added, if necessary, under UNRELEASED.
• CONTRIBUTORS entry added, if necessary.
• If it's relevant, add the documentation about your feature in the README file.
• Indicate [wip] in the title of the PR it is is not final yet. Remove [wip] when ready. Otherwise the PR will be considered complete and rejected if it's not working.

[codecov]

Codecov Report

Merging #1172 into master will increase coverage by 0.3%.
The diff coverage is 83.9%.

@@            Coverage Diff             @@
##             master   #1172     +/-   ##
==========================================
+ Coverage        40%   40.3%   +0.3%     
  Complexity       11      11             
==========================================
  Files           200     203      +3     
  Lines          5234    5264     +30     
==========================================
+ Hits           2093    2118     +25     
- Misses         3141    3146      +5

Impacted Files	Coverage Δ	Complexity Δ
app/Http/Controllers/ChangelogController.php	0% <0%> (ø)	0 <0> (?)
app/Http/Controllers/SettingsController.php	11.7% <0%> (ø)	0 <0> (ø)	⬇️
app/Instance.php	57.2% <100%> (+57.2%)	0 <0> (ø)	⬇️
app/Account.php	88.9% <100%> (+0.2%)	0 <0> (ø)	⬇️
app/Changelog.php	100% <100%> (ø)	0 <0> (?)
app/User.php	100% <100%> (ø)	0 <0> (ø)	⬇️
app/Jobs/AddChangelogEntry.php	100% <100%> (ø)	0 <0> (?)
app/Reminder.php	98% <0%> (-2%)	0% <0%> (ø)
... and 1 more

---

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[asbiin]

This file should be deleted

[asbiin]

This could have a side effect on RTL languages

[asbiin]

Nice work !

[github-actions]

This pull request has been automatically locked since there
has not been any recent activity after it was closed.
Please open a new issue for related bugs.