docs: Update release instructions

Update our release instructions with a way to run manual tasks via
`doit`. Also, add developer documentation on how to use `doit`, and some
tips and tricks.

RELEASE.md

@@ -80,7 +80,16 @@ Once we are confident that the release will be out shortly, and doesn't need any
 
 ### macOS Release
 
-This needs to happen for both Silicon and Intel chipsets.
+> [!TIP]
+> You can automate these steps from your macOS terminal app with:
+>
+> ```
+> doit clean
+> doit -n 8 apple_id=<email>                  # for Intel macOS
+> doit -n 8 apple_id=<email> macos_build_dmg  # for Apple Silicon macOS
+> ```
+
+The following needs to happen for both Silicon and Intel chipsets.
 
 #### Initial Setup
 
@@ -221,12 +230,17 @@ Rename `Dangerzone.msi` to `Dangerzone-$VERSION.msi`.
 
 ### Linux release
 
-> [!INFO]
-> Below we explain how we build packages for each Linux distribution we support.
+> [!TIP]
+> You can automate these steps from any Linux distribution with:
 >
-> There is also a `release.sh` script available which creates all
-> the `.rpm` and `.deb` files with a single command.
+> ```
+> doit clean
+> doit -n 8 fedora_rpm debian_deb
+> ```
+>
+> You can then add the created artifacts to the appropriate APT/YUM repo.
 
+Below we explain how we build packages for each Linux distribution we support.
 
 #### Debian/Ubuntu
 
@@ -268,7 +282,7 @@ or create your own locally with:
 ./dev_scripts/env.py --distro fedora --version 41 build-dev
 
 # Build the latest container (skip if already built):
-./dev_scripts/env.py --distro fedora --version 41 run --dev bash -c "cd dangerzone && poetry run ./install/common/build-image.py" 
+./dev_scripts/env.py --distro fedora --version 41 run --dev bash -c "cd dangerzone && poetry run ./install/common/build-image.py"
 
 # Create a .rpm:
 ./dev_scripts/env.py --distro fedora --version 41 run --dev bash -c "cd dangerzone && ./install/linux/build-rpm.py"

docs/developer/doit.md

@@ -0,0 +1,58 @@
+# Using the Doit Automation Tool
+
+Developers can use the [Doit](https://pydoit.org/) automation tool to create
+release artifacts. The purpose of the tool is to automate our manual release
+instructions in `RELEASE.md` file. Not everything is automated yet, since we're
+still experimenting with this tool. You can find our task definitions in this
+repo's `dodo.py` file.
+
+## Why Doit?
+
+We picked Doit out of the various tools out there for the following reasons:
+
+* **Pythonic:** The configuration file and tasks can be written in Python. Where
+  applicable, it's easy to issue shell commands as well.
+* **File targets:** Doit borrows the file target concept from Makefiles. Tasks
+  can have file dependencies, and targets they build. This makes it easy to
+  define a dependency graph (DAG) for tasks.
+* **Hash-based caching:** Unlike Makefiles, doit does not look at the
+  modification timestamp of source/target files, to figure out if it needs to
+  run them.  Instead, it hashes those files, and will run a task only if the
+  hash of a file dependency has changed.
+* **Parallelization:** Tasks can be run in parallel with the `-n` argument,
+  which is similar to `make`'s `-j` argument.
+
+## How to Doit?
+
+First, enter your Poetry shell. Then, make sure that your environment is clean,
+and you have ample disk space. You can run:
+
+```bash
+doit clean --dry-run  # if you want to see what would happen
+doit clean  # you'll be asked to cofirm that you want to clean everything
+```
+
+Finally, you can build all the release artifacts with `doit`, or a specific task
+with:
+
+```
+doit <task>
+```
+
+## Tips and tricks
+
+* You can run `doit list --all -s` to see the full list of tasks, their
+  dependencies, and whether they are up to date.
+* You can run `doit info <task>` to see which dependencies are missing.
+* You can change this line in `pyproject.toml` to `true`, to allow using the
+  Docker/Podman build cache:
+
+  ```
+  use_cache = true
+  ```
+
+* You can pass the following global parameters with `doit <param>=<value>`:
+  - `runtime`: The container runtime to use. Either `podman` or `docker`
+  - `release_dir`: Where to store the release artifacts. Default path is
+    `~/release-assets/<version>`
+  - `apple_id`: The Apple ID to use when signing/notarizing the macOS DMG.