Finished documenting scripting system.

This means the documentation is DONE (yay!)

git-svn-id: svn://svn.code.sf.net/p/magicseteditor/code/trunk@606 0fc631ac-6414-0410-93d0-97cfa31319b6

doc/script/rule_form.txt

@@ -0,0 +1,17 @@
+Rule form
+
+Some functions are available in ''rule form''.
+
+These rule form functions are functions that create a new [[type:function]].
+That new function, the rule, applies some transformation to the input and returns the result.
+
+A rule is like a normal function with all parameters given, except for the @input@.
+
+Rules are often combined using the + operator, for example:
+> # First all "a"s are replaced, then all "b"s.
+> remove_as_and_bs := replace_rule(match: "a", replace: "") +
+>                     replace_rule(match: "b", replace: "")
+> 
+> text_with_as_and_bs := "bla bla bla"
+> text_without_as_and_bs := remove_as_and_bs(text_with_as_and_bs)
+