Fix broken link in airflow.settings.yaml file

[paolaperaza]

Description

This is a hotfix PR does a few small things:

1. Fixes the broken link in the airflow_settings.yaml file that is automatically generated when a user runs $ astro dev init via the Astronomer CLI.
2. Removes the ## This feature is in Beta comment (that has been there for 2+ years...)
3. Adds improved copy that better informs the user on what this file should be used for

Old link: https://github.com/astronomer/docs/blob/main/v0.10/cli-airflow-configuration.md
New Link: https://www.astronomer.io/docs/cloud/stable/develop/customize-image#configure-airflowsettingsyaml

🎟 Issue(s)

Resolves https://github.com/astronomer/issues/issues/2850

📋 Checklist

• Rebased from the main (or release if patching) branch (before testing)
• Ran make test before taking out of draft
• Added/updated applicable tests
• Tested against Houston-API and Astronomer (if necessary).
• Communicated to/tagged owners of respective clients potentially impacted by these changes.
• Updated any related documentation

@vishwas-astro @andriisoldatenko This felt like an easy fix so I gave it a shot 😊 Let me know if I missed anything or if you have feedback on the copy here.

[codecov]

Codecov Report

Merging #411 (1bcc9b1) into main (9ab5114) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main     #411   +/-   ##
=======================================
  Coverage   56.52%   56.52%           
=======================================
  Files          32       32           
  Lines        2406     2406           
=======================================
  Hits         1360     1360           
- Misses        945      946    +1     
+ Partials      101      100    -1     

Impacted Files	Coverage Δ
docker/docker.go	27.84% <0.00%> (ø)

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[adam2k]

LGTM! 🎉