docs: Move some docs around (#4470)

* Move RELEASING.md from the top directory to docs/dev
* Move 0.x and 1.x CHANGES documents from src/doc to docs
* A couple master->main renames that were MIA

Signed-off-by: Larry Gritz <lg@larrygritz.com>

ASWF/project_intake.md

@@ -9,7 +9,7 @@ This is a checklist for TSC's to review as part of the intake process. The TSC s
   - [X] A [CONTRIBUTING.md](../CONTRIBUTING.md) file explaining to other developers and your community of users how to contribute to the project. The file should explain what types of contributions are needed and how the process works, along with how to disclose security issues responsibly ( may also point to a [SECURITY.md](../SECURITY.md) file ).
   - [ ] A [CODEOWNERS](../CODEOWNERS) or [COMMITTERS](../COMMITERS.csv) file to define individuals or teams that are responsible for code in a repository; document current project owners and current and emeritus committers.
   - [X] A [CODE_OF_CONDUCT.md](../CODE_OF_CONDUCT.md) file that sets the ground rules for participants’ behavior associated and helps to facilitate a friendly, welcoming environment. By default, projects should leverage the Linux Foundation Code of Conduct unless an alternate Code of Conduct was previously approved.
-  - [X] A [RELEASING.md](../RELEASING.md) file that provides documentation on the release methodology, cadence, criteria, etc.
+  - [X] A [RELEASING.md](docs/RELEASING.md) file that provides documentation on the release methodology, cadence, criteria, etc.
   - [X] A [GOVERNANCE.md](../GOVERNANCE.md) file that documents the project’s technical governance.
   - [ ] A [SUPPORT.md](../SUPPORT.md) file to let users and developers know about ways to get help with your project.
 - Infrastructure/Assets

CHANGES.md

@@ -5438,5 +5438,5 @@ Notable documentation changes:
 --------------
 
 For older release notes, see:
-* [CHANGES-0.x](https://github.com/AcademySoftwareFoundation/OpenImageIO/blob/master/src/doc/CHANGES-0.x.md).
-* [CHANGES-1.x](https://github.com/AcademySoftwareFoundation/OpenImageIO/blob/master/src/doc/CHANGES-1.x.md).
+* [CHANGES-0.x](https://github.com/AcademySoftwareFoundation/OpenImageIO/blob/main/src/doc/CHANGES-0.x.md).
+* [CHANGES-1.x](https://github.com/AcademySoftwareFoundation/OpenImageIO/blob/main/src/doc/CHANGES-1.x.md).

README.md

@@ -140,10 +140,10 @@ pull request (PR) mechanism.
 * [ROADMAP](docs/ROADMAP.md) is a high-level overview of the current
   development priorities for the next annual release, expected in September,
   2024.
-* [RELEASING](RELEASING.md) explains our policies and procedures for making
-  releases. We have a major, possibly-compatibility-breaking, release annually
-  in September/October, and minor bug fix and safe feature addition release at
-  the beginning of every month.
+* [RELEASING](docs/dev/RELEASING.md) explains our policies and procedures for
+  making releases. We have a major, possibly-compatibility-breaking, release
+  annually in September/October, and minor bug fix and safe feature addition
+  release at the beginning of every month.
 * [Building the docs](src/doc/Building_the_docs.md) has instructions for
   building the documentation locally, which may be helpful if you are editing
   the documentation in nontrivial ways and want to preview the appearance.

src/doc/copyr.rst

@@ -36,4 +36,4 @@ http://creativecommons.org/licenses/by/4.0/
 
 OpenImageIO incorporates code from several other software packages with
 compatible licenses. Copies of their licenses are reproduced here:
-https://github.com/AcademySoftwareFoundation/OpenImageIO/blob/master/THIRD-PARTY.md
+https://github.com/AcademySoftwareFoundation/OpenImageIO/blob/main/THIRD-PARTY.md