add simple example data and analysis script

.gitattributes

 *.hdf filter=lfs diff=lfs merge=lfs -text
+*.png filter=lfs diff=lfs merge=lfs -text

.gitignore

+.ipynb_checkpoints

README.md

@@ -32,7 +32,7 @@ Assumptions:
 
 1. On your machine, install the Git LFS extension ([here](https://git-lfs.github.com/) are some instructions).
 2. In your local repository clone, configure which types of files you want to track by LFS.
-    - For example, to let LFS keep track of HDF files, you can type: `$ git lfs track "*.hdf"`.
+    - For example, to let LFS keep track of [HDF files](https://www.hdfgroup.org/), type: `$ git lfs track "*.hdf"`.
     - This will create/change the Git configuration file [`.gitattributes`](.gitattributes).
       You should track this configuration change in Git, e.g. by the usual Git commands `$ git add .gitattributes` and `$ git commit -m "start tracking HDF files with LFS"`.  
       *Note that because the file name `.gitattributes` starts with a dot, it may be hidden from view (on Linux and MacOS, use `$ ls -a` to see it; FIXME: What to do on Windows?).*