Use a consistent convention for path references

[wbamberg]

In stumptown, HTML element pages can refer to their attributes by giving a path. They can also refer to their examples by giving a path. Unfortunately it seems we use a different convention for each:

examples:
    - examples/simple-example
    - examples/audio-element-with-video-element
    - examples/multiple-source-elements
attributes:
    element_specific: ./attributes
    global: /content/html/global_attributes

...attributes expects us to have a leading ./ for the current directory, examples omits it. We should be consistent.

@Elchi3 :

I like this one. (without any "../" or "./")

I guess we would need ../ and so on where the directory isn't under the current one?

[peterbe]

I read examples/simple-example to mean the same as ./examples/simple-example. It'd basically be the same anyway if you path.join() with the current file's __dirname.
The only one that is bothersome is /content/html/global_attributes which feels magical and would not work to use path.join with, in any way.