feat(docker): add custom image and tag env configuration (#306)

- Replace hardcoded image values with overrideable env variables
- Standardize version env var from LVA_VERSION to LVA_IMAGE_TAG
- Add new env options documentation to .env.example
- Add dev.env to gitignore
- Disable default mic noise suppression in dev compose

BREAKING CHANGE: LVA_VERSION env var replaced with LVA_IMAGE_TAG

.gitignore

@@ -21,5 +21,6 @@ venv/
 
 # Docker
 .env
+dev.env
 version.txt
 version_githash.txt