doc: mention version subcommand

We didn't have any mention of `--version` in our docs but let's make
sure we document the new `version` subcommand.

Signed-off-by: Simon de Vlieger <cmdr@supakeen.com>

Author: supakeen

README.md

@@ -261,6 +261,25 @@ $ image-builder list --format=json
 ]
 ```
 
+### Version information
+
+To show version information about the installed `image-builder`:
+```console
+$ image-builder version
+image-builder:
+  version: 0.5
+  commit: abc123
+  dependencies:
+    images: v0.100.0
+    osbuild: "105"
+```
+
+The output format can be changed with `--format`, supported formats are `yaml` (default) and `json`:
+```console
+$ image-builder version --format=json | jq '.["image-builder"].version'
+"0.5"
+```
+
 ## Modifying the set of used repositories
 
 There are various ways to add extra repositories or override the default

doc/01-usage.md

@@ -341,6 +341,36 @@ $ image-builder manifest --arch aarch64 minimal-raw-xz
 # ... output ...
 ```
 
+## `image-builder version`
+
+The `version` command prints version information about the `image-builder` binary including its dependencies.
+
+```console
+$ image-builder version
+image-builder:
+  version: 0.5
+  commit: abc123
+  dependencies:
+    images: v0.100.0
+    osbuild: "105"
+```
+
+The output format can be changed with `--format`. Available formats are `yaml` (default) and `json`:
+
+```console
+$ image-builder version --format=json
+{
+  "image-builder": {
+    "version": "0.5",
+    "commit": "abc123",
+    "dependencies": {
+      "images": "v0.100.0",
+      "osbuild": "105"
+    }
+  }
+}
+```
+
 ## Blueprints
 
 Images can be customized with [blueprints](https://osbuild.org/docs/user-guide/blueprint-reference). For example we could build the `qcow2` we built above with some customizations applied.