Documentation: spelling and grammar fixes

Signed-off-by: Ville Skyttä <ville.skytta@iki.fi>
Reviewed-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/technical/api-directory-listing.txt

@@ -54,7 +54,7 @@ The notable options are:
 	this case, the contents are returned as individual entries.
 +
 If this is set, files and directories that explicitly match an ignore
-pattern are reported. Implicity ignored directories (directories that
+pattern are reported. Implicitly ignored directories (directories that
 do not match an ignore pattern, but whose contents are all ignored)
 are not reported, instead all of the contents are reported.
 

Documentation/technical/api-gitattributes.txt

@@ -146,7 +146,7 @@ To get the values of all attributes associated with a file:
 
 * Iterate over the `attr_check.items[]` array to examine
   the attribute names and values.  The name of the attribute
-  described by a  `attr_check.items[]` object can be retrieved via
+  described by an `attr_check.items[]` object can be retrieved via
   `git_attr_name(check->items[i].attr)`.  (Please note that no items
   will be returned for unset attributes, so `ATTR_UNSET()` will return
   false for all returned `attr_check.items[]` objects.)

Documentation/technical/commit-graph-format.txt

@@ -18,7 +18,7 @@ metadata, including:
   the graph file.
 
 These positional references are stored as unsigned 32-bit integers
-corresponding to the array position withing the list of commit OIDs. We
+corresponding to the array position within the list of commit OIDs. We
 use the most-significant bit for special purposes, so we can store at most
 (1 << 31) - 1 (around 2 billion) commits.