[webcomponents] added guts of custom elements semantics section (#26)

not finished but far enough along to be reviewed
You can merge this Pull Request by running:

  git pull https://github.com/stevefaulkner/webcomponents gh-pages

Or you can view, comment on it, or merge it online at:

  https://github.com/w3c/webcomponents/pull/26

-- Commit Summary --

  * custom element semantics
  * added link
  * added text to code example
  * chnaged example name to taco-button
  * filling out example
  * filled out the examples
  * code style

-- File Changes --

    M spec/custom/index.html (48)

-- Patch Links --

https://github.com/w3c/webcomponents/pull/26.patch
https://github.com/w3c/webcomponents/pull/26.diff

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Reply to this email directly or view it on GitHub:
https://github.com/w3c/webcomponents/pull/26