pretty-formats.txt: use generic terms for hash

Since Git is planning on upgrading from SHA-1 to be more hash-agnostic,
replace specific references to SHA-1 with more generic terminology.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/pretty-formats.txt

@@ -4,7 +4,7 @@ PRETTY FORMATS
 If the commit is a merge, and if the pretty-format
 is not 'oneline', 'email' or 'raw', an additional line is
 inserted before the 'Author:' line.  This line begins with
-"Merge: " and the sha1s of ancestral commits are printed,
+"Merge: " and the hashes of ancestral commits are printed,
 separated by spaces.  Note that the listed commits may not
 necessarily be the list of the *direct* parent commits if you
 have limited your view of history: for example, if you are
@@ -20,20 +20,20 @@ built-in formats:
 
 * 'oneline'
 
-	  <sha1> <title line>
+	  <hash> <title line>
 +
 This is designed to be as compact as possible.
 
 * 'short'
 
-	  commit <sha1>
+	  commit <hash>
 	  Author: <author>
 
 	      <title line>
 
 * 'medium'
 
-	  commit <sha1>
+	  commit <hash>
 	  Author: <author>
 	  Date:   <author date>
 
@@ -43,7 +43,7 @@ This is designed to be as compact as possible.
 
 * 'full'
 
-	  commit <sha1>
+	  commit <hash>
 	  Author: <author>
 	  Commit: <committer>
 
@@ -53,7 +53,7 @@ This is designed to be as compact as possible.
 
 * 'fuller'
 
-	  commit <sha1>
+	  commit <hash>
 	  Author:     <author>
 	  AuthorDate: <author date>
 	  Commit:     <committer>
@@ -65,7 +65,7 @@ This is designed to be as compact as possible.
 
 * 'email'
 
-	  From <sha1> <date>
+	  From <hash> <date>
 	  From: <author>
 	  Date: <author date>
 	  Subject: [PATCH] <title line>
@@ -75,7 +75,7 @@ This is designed to be as compact as possible.
 * 'raw'
 +
 The 'raw' format shows the entire commit exactly as
-stored in the commit object.  Notably, the SHA-1s are
+stored in the commit object.  Notably, the hashes are
 displayed in full, regardless of whether --abbrev or
 --no-abbrev are used, and 'parents' information show the
 true parent commits, without taking grafts or history