Documentation/config.txt: have a separate "Values" section

The various types of values set to the configuration variables
deserve more than a brief footnote mention in the syntax section,
and it will be more so after the later steps of this clean up
effort.

Move the mention of booleans from the syntax section to this new
section, and describe how human-readble integers can be spelled with
scaling there.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/config.txt

@@ -75,14 +75,6 @@ The following escape sequences (beside `\"` and `\\`) are recognized:
 and `\b` for backspace (BS).  No other char escape sequence, nor octal
 char sequences are valid.
 
-The values following the equals sign in variable assign are all either
-a string, an integer, or a boolean.  Boolean values may be given as yes/no,
-1/0, true/false or on/off.  Case is not significant in boolean values, when
-converting value to the canonical form using '--bool' type specifier;
-'git config' will ensure that the output is "true" or "false".
-
-Some variables may require a special value format.
-
 
 Includes
 ~~~~~~~~
@@ -124,6 +116,37 @@ Example
 		path = foo ; expand "foo" relative to the current file
 		path = ~/foo ; expand "foo" in your $HOME directory
 
+
+Values
+~~~~~~
+
+Values of many variables are treated as a simple string, but there
+are variables that take values of specific types and there are rules
+as to how to spell them.
+
+boolean::
+
+       When a variable is said to take a boolean value, many
+       synonyms are accepted for 'true' and 'false'; these are all
+       case-insensitive.
+
+       true;; Boolean true can be spelled as `yes`, `on`, `true`,
+		or `1`.  Also, a variable defined without `= <value>`
+		is taken as true.
+
+       false;; Boolean false can be spelled as `no`, `off`,
+		`false`, or `0`.
++
+When converting value to the canonical form using '--bool' type
+specifier; 'git config' will ensure that the output is "true" or
+"false" (spelled in lowercase).
+
+integer::
+       The value for many variables that specify various sizes can
+       be suffixed with `k`, `M`,... to mean "scale the number by
+       1024", "by 1024x1024", etc.
+
+
 Variables
 ~~~~~~~~~