Update readme with inclusion criteria, process and other info

Author: bbhtt

README.md

@@ -1,63 +1,78 @@
-This repository contains commonly shared modules and is intended to be used as a git submodule.
+## Flathub shared modules
 
-Each submodule may include additional instructions to be used properly. Please check the folder containing that module to see if anything extra needs to be done.
+This repository contains Flatpak build recipes of commonly shared
+modules and is intended to be used as a git submodule. Each submodule
+may include additional instructions to be used properly. Please check
+the folder containing that module to see if anything extra needs to be
+done.
 
-## Adding
+### Adding
 
 To use shared modules for packaging an application, add the submodule:
 
-```
+```sh
 git submodule add https://github.com/flathub/shared-modules.git
 ```
 
-## Usage
+### Usage
 
 Then modules from this repository can be specified in an application
 manifest.
 
 ```json
 "modules": [
   "shared-modules/SDL/SDL-1.2.15.json",
-  {
-    "name": "foo"
-  }
 ]
 ```
 And for a YAML manifest:
-```YAML
+
+```yaml
 modules:
   - shared-modules/SDL/SDL-1.2.15.json
-
-  - name: foo
 ```
 
-## Updating
+### Updating
 
 To update the submodule:
 
-```
+```sh
 git submodule update --remote --merge
 ```
 
-## Removing
+To automate updates, [dependabot](https://docs.github.com/en/code-security/getting-started/dependabot-quickstart-guide)
+can be used but please limit the update frequency to not more than once
+or twice a week.
+
+### Removing
 
 To remove the submodule:
 
-```
+```sh
 git submodule deinit -f -- shared-modules
 rm -rf .git/modules/shared-modules
 git rm -f shared-modules
 rm .gitmodules
 ```
 
-We provide an automatic updating mechanism for submodules located here. In order to utilize it:
+### External data checker
+
+We provide an automatic updating mechanism for submodules located here.
+In order to utilize it [set up x-checker-data](https://github.com/flathub/flatpak-external-data-checker)
+for your sources and they will be checked for updates in a weekly basis.
+
+### Inclusion criteria
+
+- The module must be widely used on [Flathub](https://github.com/flathub)
+  by actively maintained applications.
+
+- The module must not be provided by any current branch of the runtimes.
 
-- Set up x-checker-data for your sources: https://github.com/flathub/flatpak-external-data-checker#url-checker
+- The module manifest must be in JSON format.
 
-And it will check for updates in a weekly basis.
+### Inclusion process
 
-Please do not request adding modules unless they are widely used in
-the Flathub repository.
+Please open a [pull request](https://github.com/flathub/shared-modules/pulls)
+with the module manifest and add yourself as a [codeowner](https://github.com/flathub/shared-modules/blob/master/CODEOWNERS)
+of that module.
 
-All shared modules manifests in this repository are, and need to be, in the JSON format,
-which is supported by both Flatpak manifest formats, JSON and YAML.
+The manifest must be buildable with the latest Freedesktop SDK runtime.