Describe how to see commits since forking from master

The command in this tip avoids showing merge commits because sometimes
developers will merge `master` into their feature branch in the course
of development, especially when that feature is in development for a
long time.  This tip focuses on showing only those commits which
introduce new changes and ignores those merge commits for this reason.
It also displays the commits in reverse chronological order, oldest to
newest, so that the output shows the development of a feature branch
in "historical" order.

Signed-off-by: Eric James Michael Ritz <ejmr@plutono.com>

Author: Eric James Michael Ritz

README.md

@@ -27,6 +27,7 @@
 * [Stage parts of a changed file, instead of the entire file](https://github.com/git-tips/tips#stage-parts-of-a-changed-file-instead-of-the-entire-file)
 * [Get git bash completion](https://github.com/git-tips/tips#get-git-bash-completion)
 * [What changed since two weeks?](https://github.com/git-tips/tips#what-changed-since-two-weeks)
+* [See all commits made since forking from master](https://github.com/git-tips/tips#see-all-commits-made-since-forking-from-master)
 * [Pick commits across branches using cherry-pick](https://github.com/git-tips/tips#pick-commits-across-branches-using-cherry-pick)
 * [Find out branches containing commit-hash](https://github.com/git-tips/tips#find-out-branches-containing-commit-hash)
 * [Git Aliases](https://github.com/git-tips/tips#git-aliases)
@@ -177,6 +178,11 @@ curl http://git.io/vfhol > ~/.git-completion.bash && echo '[ -f ~/.git-completio
 git whatchanged --since='2 weeks ago'
 ```
 
+## See all commits made since forking from master
+```sh
+git log --no-merges --stat --reverse master..
+```
+
 ## Pick commits across branches using cherry-pick
 ```sh
 git checkout <branch-name> && cherry-pick <commit-ish>

tips.json

@@ -97,6 +97,10 @@
       "title": "What changed since two weeks?",
       "tip": "git whatchanged --since='2 weeks ago'"
   },
+  {
+      "title": "See all commits made since forking from master",
+      "tip": "git log --no-merges --stat --reverse master.."
+  },
   {
       "title": "Pick commits across branches using cherry-pick",
       "tip": "git checkout <branch-name> && cherry-pick <commit-ish>"