Metafont formatting instructions (issue 13400046)

[PhilEHolmes]

Reviewers: lemzwerg, dak,

Message:
Please review

Description:
An attempt to codify and illustrate how to indent LilyPond's metafont
formatting rules.

Please review this at https://codereview.appspot.com/13400046/

Affected files (+14, -6 lines):
  M Documentation/contributor/feta-font.itexi


Index: Documentation/contributor/feta-font.itexi
diff --git a/Documentation/contributor/feta-font.itexi  
b/Documentation/contributor/feta-font.itexi
index  
78021ae8d73c858a3be151dc9e3888c90aa7b983..67987b949798977504eec2a671042ba4032d3b8c  
100644
--- a/Documentation/contributor/feta-font.itexi
+++ b/Documentation/contributor/feta-font.itexi
@@ -118,15 +118,23 @@ make

 There are special formatting rules for METAFONT files.

-Tabs are used for indentation.
+Tabs are used for the indentation of commands.

 When a path contains more than two points, put each point on a
-separate line, with the operator at the beginning  of the line:
+separate line, with the operator at the beginning of the line.
+The operators are indented to the same depth as the initial point
+on the path using spaces.  The indentation mechanism is illustrated
+below, with @code{--->} indicating a tab character and any other
+indentation created using spaces.

 @example
-fill z1
-     -- z2
-     -- z3
-     .. cycle;
+def draw_something (test) =
+--->if test:
+--->--->fill z1
+--->--->     -- z2
+--->--->     -- z3
+--->--->     .. cycle;
+--->fi;
+enddef;
 @end example