docs(examples): Remove IE9 text track HTML markup in the doc/examples, and update to use video.js v7.0 (#5192)
Video.js v7 drops support for versions of IE prior to IE11, so examples should not reference earlier versions.
* Fix the doc/example/elephantsdream/index.html file, add an index of doc/examples, and update CDN links to use video.js v5.19.
* Add poster from CDN to Elephants Dream examples.
See videojs/cdn#3
- Added a guide note about skipping analytics tracking on the CDN
- Updated videojs-font
- Added videojs-ie8 as a dependency
- Updated the examples directory URLs and added to dist
- Updated CSS to override font path