Multiple Example Pages: Fix source URI for AT support tables and add new AT support tables where available

[mcking65]

The URI for sourcing AT support table data has changed, and more support tables are now available. This change:

1. Modifies the path of the source URI for existing AT support tables to include "/apg".
2. Adds assistive technology support tables for the below list of examples.

Modified existing examples

1. Alert Example
2. Color Viewer Slider
3. Command Button Example
4. Link Example 1 (span element with text content)
5. Modal Dialog Example
6. Navigation Menu Button
7. Radio Group Example Using aria-activedescendant, CANDIDATE report
8. Toggle Button

Examples with newly added AT support tables

1. accordion (link verified)
2. Action Menu Button Example Using aria-activedescendant (linked verified)
3. Action Menu Button Example Using element.focus (linked verified)
4. Disclosure Navigation Menu Example (linked verified)
5. Disclosure of Answers to Frequently Asked Questions Example (link verified)
6. Link Example 2 (img element with alt attribute) (link verified)
7. Link Example 3 (CSS :before content property on a span element) (link verified)
8. Media Seek Slider (link verified)
9. Radio Group Example Using Roving tabindex (link verified)
10. Switch Example (link verified)
11. Switch Example Using HTML Button (link verified)
12. Tabs with Manual Activation (link verified)
13. Vertical Temperature Slider (link verified)

Preview

Preview WAI site changes in the compare branch