Add Dailymotion to list of supported services

[PChandonnay]

Dailymotion (French equivalent to YouTube)

Example video: https://www.dailymotion.com/video/xu50vh

This service runs fine on the deprecated EmbedVideo extension: https://wiki.halo.fr/Halo_4_:_Forward_Unto_Dawn#.C3.89pisodes

[octfx]

Dailymotion was implemented in 1b1323068a54e65a6a6f9a041b2d366b45150ef2 and should work in the development branch

[PChandonnay]

Wonderful, it just needs to be added to the list of supported platforms in docs then. I edited the title accordingly.

[octfx]

Information added to the readme and released in v3.2.8