automated update to example web docs

[ryancoe]

@gbacelli noticed that web documentation for chebfun is built using the MATLAB publish command.

https://www.chebfun.org/docs/guide/guide01.html

While I think we might need to complete #97 for this to be totally automated, at the very least implementing this would save the user the tedious work of correcting the line numbers in example.rst by hand.

I gave this a try with our existing example.m file (obviously you can write the .m to better support this - chebfun also notes that they use a custom style sheet):

>> publish('example.m','html')

ans =

    '/Users/rcoe/Documents/WecOptTool/WecOptTool/html/example.html'

[H0R5E]

It would certainly be nice to not have to update those line numbers!

There are a couple of downside / challenges to this:

1. The actual example file is going to have a lot more comments than code
2. The formatting is going to look a bit different compared to the rest of the sphinx docs
3. Linking to other parts of the docs will be quite verbose (and unreliable?)
4. We won't be able to automate this in travis (until we get CI unit testing for MATLAB #97) so we would have to generate and place the generated file manually before merging.

It's probably worth a try to see how it compares to what we have.

[ryancoe]

1. yes, very true
2. perhaps, but I think that this can be partially addressed by setting the stylesheet (not sure how cumbersome this would be and/or whether we can find something existing on the web)
3. true, may have to reduce the degree to which this is done?
4. yes, would still be a checkbox in the PR template