Update readme and license

Author: fwkoch

LICENSE

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+The MIT License (MIT)
+
+Copyright (c) 2017 Franklin Koch
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

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 # gitproj-diff
+
 Easy links for your git project diffs!
+
+## Purpose
+
+[git-project](https://github.com/aranzgeo/git-project) enables smooth project
+and sub-repository management when all component repositories are rapidly changing.
+Unfortunately, when sub-repositories change, this only shows up in the parent repo
+as a one line diff with the old and new commit references.
+
+This chrome extension turns those one line diffs in github into links that
+take you directly to the compare view in the sub-repo.
+
+## Installation
+
+This extension may be installed as an unpacked extension in developer mode:
+
+1. Navigate to `chrome://extensions`
+2. Check "Developer mode" box
+3. Click "Load unpacked extension..."
+4. Navigate to and select the `gitproj-diff/` folder
+
+You may also need to set up aliases. This is a dictionary of library nickname keys
+and actual library name values.
+
+For example, if your .gitproj file looks like:
+
+```
+version: 0.1.0
+repos:
+       MSR deps/my-sub-repo [email protected]:org/my-sub-repo.git
+states:
+       MSR dev bea52b0fde4a896139b1526b457837b07e6dd987
+```
+
+you need to set up:
+```javascript
+...
+var aliases = {
+    "MSR": "my-sub-repo",
+}
+...
+```
+
+## Limitations
+
+- All repositories and sub-repositories must be under the same user/org.
+- Changes to github HTML will most likely break this extension.
+- The Javascript code isn't exceptionally beautiful...
+
+## Acknowledgments
+
+This extension was originally based on a template created by Tom Maxwell,
+available [here](https://9to5google.com/2015/06/14/how-to-make-a-chrome-extensions/).