docs: point framework integration links to the doc in the README

[Baldinof]

Reason for This PR

There is multiple packages supporting RR for Symfony and Laravel, I think it's fair to link to the doc pages that list the available solutions

Description of Changes

Links in the README.md file

License Acceptance

By submitting this pull request, I confirm that my contribution is made under the terms of the MIT license.

PR Checklist

[Author TODO: Meet these criteria.]
[Reviewer TODO: Verify that these criteria are met. Request changes if not]

• All commits in this PR are signed (git commit -s).
• The reason for this PR is clearly provided (issue no. or explanation).
• The description of changes is clear and encompassing.
• Any required documentation changes (code and docs) are included in this PR.
• Any user-facing changes are mentioned in CHANGELOG.md.
• All added/changed functionality is tested.

[codecov]

Codecov Report

Merging #1562 (e88195f) into master (99d10ed) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #1562   +/-   ##
=======================================
  Coverage   40.19%   40.19%           
=======================================
  Files          16       16           
  Lines         821      821           
=======================================
  Hits          330      330           
  Misses        464      464           
  Partials       27       27           

[rustatian]

Thanks @Baldinof 👍🏻