Update options.yml documentation

Author: cytopia

doc/contributor/PHP-EXT-options.yml.md

@@ -18,7 +18,7 @@ These options are purely for the module generator to decide whether or not to bu
 * Required: Yes
 * Type: `str`
 
-The lower-case name of the extension as it is shown by `php -m`.
+The lower-case name of the extension as it is shown by `php -m` (must match directory name).
 
 
 ### `exclude`

doc/contributor/PHP-TOOL-options.yml.md

@@ -9,3 +9,45 @@ PHP Tools: `options.yml` |
 
 
 # Tool definition: `options.yml`
+
+These options are purely for the tool generator to decide whether or not to build the tool and in what order to build it (order of dependencies).
+
+
+### `name`
+
+* Required: Yes
+* Type: `str`
+
+The lower-case name of the tool (must match directory name).
+
+
+### `exclude`
+
+* Required: Yes
+* Type: `list[str]`
+* Empty: `[]`
+
+Add PHP versions to exclude from building/installing this tool. This could be due to build errors or deprecations.
+
+Example:
+```yaml
+# Exclude PHP 5.2 and PHP 5.3
+exclude: [5.2, 5.3]
+```
+
+
+### `depends`
+
+* Required: Yes
+* Type: `list[str]`
+* Empty: `[]`
+
+If this tool requires another tool to be present prior building/installing (or just to function properly during run-time), you have to specify them in this list. The tool generator will then ensure to build all available tools in order of dependencies.
+
+Example:
+```yaml
+# Before installing the current tool, it will be ensured that
+# jq is build and installed beforehand.
+depends_build:
+  - jq
+```