doc: Add a common documentation for for the rule components.

docs/common/rule.ldoc

@@ -0,0 +1,46 @@
+---
+
+--- A table which content will be used to set the target object properties.
+--
+-- foo
+--
+-- @rulecomponent properties
+-- @param table
+-- @see callbacks
+
+--TODO add ^
+-- @DOC_text_gears_matcher_properties_EXAMPLE@
+
+--- A list of callback function to call *after* the properties have been apploed.
+-- @rulecomponent callbacks
+-- @param table
+-- @see properties
+
+--- A table which content will be compared to the target object current properties.
+--
+-- @rulecomponent rule
+-- @param table
+-- @see rule_any
+-- @see except
+
+--- Similar to `rule`, but each entry is a table with multiple values.
+--
+--
+-- @rulecomponent rule_any
+-- @param table
+-- @see rule
+-- @see except_any
+
+--- The negative equivalent of `rule`.
+--
+-- @rulecomponent except
+-- @param table
+-- @see rule
+-- @see except_any
+
+--- The negative equivalent of `rule_any`.
+--
+-- @rulecomponent except_any
+-- @param table
+-- @see rule
+-- @see except