Replace 'Wordpress' with 'WordPress' to use correct camel casing according to the WordPress Wordmark and Trademark

Add a new working example for hook_civicrm_buildAmount

This opening tag used to be required for syntax highlighting to work
properly in code blocks. Now we no longer need it.

This caused me a few hours of pain today.  Hopefully this will save someone else that time!

(so that we can avoid a broken link in a wiki page we're migrating)

I was just trying this hook out in 4.7.22, the result pulls out the first element of the return and lists that on the case summary page. From the old docs, just gets the first key/val pair, then displays the first character of the label/value string.

We have a template for how to fix core files to support this hook properly. This commit points people to it.

I tried using this code with the short name and it didn't work.
When I changed my code to use my extension's long name, it worked.

- Add function signature
- Better markdown formatting
- Improve readbility of example code

Examples and explanations on this page use $objectType, so standardizing on that.

The paragraph between the "Summary" heading and the next heading needs
to be short because we use this paragraph when generating the hooks
summary page.

To document the changes in CRM-20926, we need some kind of doc about the XML
menu structure...  which doesn't seem to exist.

This change fixes some quirks in the `h_c_xmlMenu` doc and also adds a
section for the XML.  This revision is not exhausive, but it covers some
common ones, and it's enough that we can add-in more.

Run the following command to do so:
./bin/hook-summary.py