[minor] correct capitalization consistency

[shawna-slh]

For example headings are inconsistently capitalized in:

Transcripts and Scripts
Dubbing scripts
Audio Description scripts
Other uses
Example documents
Basic document structure
Audio Description Examples
Dubbing Examples
...

And the document title is:

Dubbing and Audio description Profiles of TTML2

[nigelmegitt]

Thanks @shawna-slh - the only inconsistent capitalization I can see is that the headings that include "Examples" should have "examples" instead. Not sure what else needs changing - what would you suggest?

The document title is capitalized like that to indicate why the abbreviated short name is DAPT, rather than, say, DADPT.