Publishing to Maven Central requires spring-boot-starter-parent to
declare its license and developers. When a user then uses
spring-boot-starter-parent as their project's parent, these values
are inherited and this is almost certainly unwanted.

This commit updates the documentation to recommend and demonstrate
overriding the license and developers that are inherited from the
starter parent.

Closes gh-18532

Previously, the security risks and our recommendations on how to
mitigate them were not documented as clearly as they could have been.
This commit makes some changes to try to address this:

1. The security risk is now noted at the beginning of the section
2. The recommendation to use SSL is now documented more prominently
   and an alternative recommendation to only use remote support on
   a trusted network has been added.
3. The example secret has been removed to prevent copy and paste
4. A recommendation to use a secret that is unique and strong has been
   added

Closes gh-18825

* pr/18870:
  Polish "Document Settings as jooq supported auto-configuration type"
  Document Settings as jooq supported auto-configuration type

Closes gh-18870

See gh-18870

See gh-18870

Closes gh-18763

Closes gh-18874

Closes gh-18765

Closes gh-18865

Closes gh-18761

Closes gh-18860

Closes gh-18859

Closes gh-18858

Closes gh-18743

* pr/18848:
  Drop JDK 12-based CI

Closes gh-18848

See gh-18848

* pr/18845:
  Test the Gradle Plugin against Gradle 5.6.4

Closes gh-18845

See gh-18845

Closes gh-18737

Closes gh-17261

Closes gh-18791

Closes gh-18790

Closes gh-18789

Closes gh-18788

Closes gh-18787

Closes gh-18786

Closes gh-18785

Closes gh-18784

Closes gh-18783

Closes gh-18782

Closes gh-18781

Closes gh-18780

Closes gh-18779

Closes gh-18778

See gh-18743

See gh-18765

See gh-18763

See gh-18761

Closes gh-18739

* pr/18752:
  Fix OAuth2 Client redirect-uri references

Closes gh-18752