doc: fix ASCII art tab spacing

Followup to 5dd05ebf ("doc: fix merge-base ASCII art tab spacing", 2016-10-21)

Signed-off-by: Andreas Heiduk <asheiduk@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-bisect-lk2009.txt

@@ -633,11 +633,11 @@ and so at step 3) we compute f(X).
 Let's take the following graph as an example:
 
 -------------
-	    G-H-I-J
-	   /       \
+            G-H-I-J
+           /       \
 A-B-C-D-E-F         O
-	   \       /
-	    K-L-M-N
+           \       /
+            K-L-M-N
 -------------
 
 If we compute the following non optimal function on it:
@@ -649,25 +649,25 @@ g(X) = min(number_of_ancestors(X), number_of_descendants(X))
 we get:
 
 -------------
-	    4 3 2 1
-	    G-H-I-J
+            4 3 2 1
+            G-H-I-J
 1 2 3 4 5 6/       \0
 A-B-C-D-E-F         O
-	   \       /
-	    K-L-M-N
-	    4 3 2 1
+           \       /
+            K-L-M-N
+            4 3 2 1
 -------------
 
 but with the algorithm used by git bisect we get:
 
 -------------
-	    7 7 6 5
-	    G-H-I-J
+            7 7 6 5
+            G-H-I-J
 1 2 3 4 5 6/       \0
 A-B-C-D-E-F         O
-	   \       /
-	    K-L-M-N
-	    7 7 6 5
+           \       /
+            K-L-M-N
+            7 7 6 5
 -------------
 
 So we chose G, H, K or L as the best bisection point, which is better
@@ -773,7 +773,7 @@ forked of the main branch at a commit named "D" like this:
 -------------
 A-B-C-D-E-F-G  <--main
        \
-	H-I-J  <--dev
+        H-I-J  <--dev
 -------------
 
 The commit "D" is called a "merge base" for branch "main" and "dev"

Documentation/git-checkout.txt

@@ -311,9 +311,9 @@ branch refers to a specific commit. Let's look at a repo with three
 commits, one of them tagged, and with branch 'master' checked out:
 
 ------------
-	   HEAD (refers to branch 'master')
-	    |
-	    v
+           HEAD (refers to branch 'master')
+            |
+            v
 a---b---c  branch 'master' (refers to commit 'c')
     ^
     |
@@ -329,9 +329,9 @@ to commit 'd':
 ------------
 $ edit; git add; git commit
 
-	       HEAD (refers to branch 'master')
-		|
-		v
+               HEAD (refers to branch 'master')
+                |
+                v
 a---b---c---d  branch 'master' (refers to commit 'd')
     ^
     |
@@ -398,7 +398,7 @@ at what happens when we then checkout master:
 ------------
 $ git checkout master
 
-	       HEAD (refers to branch 'master')
+               HEAD (refers to branch 'master')
       e---f     |
      /          v
 a---b---c---d  branch 'master' (refers to commit 'd')

Documentation/git-merge-base.txt

@@ -154,13 +154,13 @@ topic origin/master`, the history of remote-tracking branch
 `origin/master` may have been rewound and rebuilt, leading to a
 history of this shape:
 
-			 o---B2
+	                 o---B2
 	                /
 	---o---o---B1--o---o---o---B (origin/master)
 	        \
-		 B0
+	         B0
 	          \
-		   D0---D1---D (topic)
+	           D0---D1---D (topic)
 
 where `origin/master` used to point at commits B0, B1, B2 and now it
 points at B, and your `topic` branch was started on top of it back