Merge branch 'f-macro-doc' into 'dev'

DOC: fix an example and clarify how macros work

See merge request !49

src/doc/macros.rst

@@ -37,7 +37,7 @@ The same version using cfood macros could be defined as follows:
         name: null
         filename: null
       definition:
-        ${name}_filename
+        ${name}_filename:
           type: SimpleFile
           match: $filename
           records:
@@ -57,6 +57,8 @@ The same version using cfood macros could be defined as follows:
         filename: ^README.md$
 
 
+The "MarkdownFile" key and its value will be replaced by everything that is 
+given below "definition" in the Macro.