Update title of documentation page (#7368)
Update title of documentation page (#7368)

* Update title of documentation page

The title of this page mentioned videos because in the original version of this document it _did_ cover adding embedded videos. However, this page no longer mentions videos aside from the title.

* Fix length of underline
zerolab/wagtail,wagtail/wagtail,mixxorz/wagtail,thenewguy/wagtail,wagtail/wagtail,jnns/wagtail,jnns/wagtail,rsalmaso/wagtail,thenewguy/wagtail,gasman/wagtail,torchbox/wagtail,gasman/wagtail,mixxorz/wagtail,gasman/wagtail,gasman/wagtail,thenewguy/wagtail,zerolab/wagtail,rsalmaso/wagtail,thenewguy/wagtail,torchbox/wagtail,wagtail/wagtail,thenewguy/wagtail,mixxorz/wagtail,rsalmaso/wagtail,gasman/wagtail,mixxorz/wagtail,zerolab/wagtail,wagtail/wagtail,zerolab/wagtail,jnns/wagtail,mixxorz/wagtail,wagtail/wagtail,rsalmaso/wagtail,zerolab/wagtail,torchbox/wagtail,torchbox/wagtail,rsalmaso/wagtail,jnns/wagtail