chore: Document compatibility (#168)

`README.md`:
- Guide users towards using 11.11 because it is the most likely to give
  them a smooth experience since it is what I have done most of my
  development with. In particular it still allows the root ssh user on
  which many of our tools still depend.

`docs/compatibility.md`:
- Include the rationale for prioritizing 11.11 over both 10.12 and 12.y
  because it feels important that readers understand this reason; users
  could find the ordering of the list unintuitive and contributors
  would probably benefit from adopting the same mindset.
- 9.80 is written without a trailing `.z` because SemVer was not
  adopted until 10.
- Versions older than LTS 2020 are excluded because they are not
  generally supported.

README.md

@@ -30,7 +30,7 @@ To quickly start a new app, see [acap-rs-app-template](https://github.com/AxisCo
 
 ## Getting started
 
-There are multiple ways to set up a development environment, but the recommended way is using a dev container.
+The recommended setup is using the [dev container](#dev-container) and the most recent LTS version of AXIS OS [^1].
 
 ### Dev container
 
@@ -241,3 +241,5 @@ be resolved by either
 [ACAP]: https://axiscommunications.github.io/acap-documentation/
 
 [Rust]: https://doc.rust-lang.org/
+
+[^1]: Compatibility with various host and target environments are explored and explained in [compatibility](docs/compatibility.md)

docs/compatibility.md

@@ -0,0 +1,28 @@
+The primary factor determining what this project is the personal preferences of its contributors, who volunteer.
+
+That being said these notes should help users manage expectations and guide decisions of contributors.
+
+## Development environment
+
+1. Dev Container
+   - A reproducible environment where everything _should_ work.
+   - Expect help troubleshooting if something does not work.
+2. Debian
+   - Can do everything the dev container can do _if_ set up correctly.
+   - In practice the best tested environment, but may not be fully documented.
+   - Expect to do your own troubleshooting since it is not a reproducible environment.
+3. Ubuntu
+   - Some dependencies may not cross-compile.
+4. MacOS
+   - Cross compilation does not work.
+5. WSL
+6. Windows
+
+## AXIS OS
+
+The most recent LTS is the most prioritized target because it strikes a balance between being feature richness and stability.
+
+1. LTS 2024 (11.11.z)
+2. Active (12.y.z)
+3. LTS 2022 (12.12.z)
+4. LTS 2020 (9.80)