Added a bunch of changes

GETTING-STARTED-WITH-GIT.md

@@ -10,7 +10,7 @@ Let us create an _empty_ `git` repository. It is analogous to buying a bookshelf
 > `Initialized empty Git repository in git-tutorial/examples/prime/.git/`
 
 ## Create Content
-Let us say, you are asked to write a prime number generator in C++ by your teacher. So we are going to create a bare-bones C++ file called `prime.cpp`.
+Let us say, you are asked to write a prime number checker in C++ by your teacher. So we are going to create a bare-bones C++ file called `prime.cpp`.
 
 Create a file named `prime.cpp` inside your prime directory and paste the following,
 
@@ -22,7 +22,7 @@ Create a file named `prime.cpp` inside your prime directory and paste the follow
         return 0;
     }
 
-You have read somewhere that the recommended way to work with `git` is ___commit early, commit often___. So you are thinking, "this might be a good time to take a snapshot of my file and put it in the repository". Let's do that.
+You have read somewhere that the recommended way to work with `git` is ___commit early, commit often___. So you are thinking, "this might be a good time to take a snapshot of my file and put it in the repository." Let's do that.
 
     $ git add prime.cpp
     $ git commit -m 'First version'

REVERT-CHANGES.md

@@ -0,0 +1,28 @@
+# Revert Changes
+Hopefully you have not forgotten about your assignment from the last chapter. But who wants to do an assignment? (Not me at least.) Luckily, you have a friend who has already done it. Let's copy his assignment,
+
+    bool CopiedIsPrime(int n)
+    {
+        for (int i = 2; i < n; ++i)
+        {
+            if (n % i == 0)
+                return false;
+        }
+        return true;
+    }
+
+Paste this function just before `int main()`. Commit your changes,
+
+    $ git commit prime.cpp -m 'Borrowed IsPrime() from a friend (don't tell the teacher)'
+
+> Note that `git add` is not required here since we are explicitly mentioning the name of the file we want to commit.
+
+That's it. An assignment well done!
+
+Well, not quite...
+Unfortunately for you, your teacher is also a frequent visitor of GitHub and he sees your commit message. Now he is really angry. He screams, "Either you do it yourself or I will fail you." So you type,
+
+    $ git reflog
+
+> `4c29248 HEAD@{0}: commit: Borrowed IsPrime() from a friend (don't tell the teach
+974dbe5 HEAD@{1}: commit (initial): First version`