* Fixed a typo in Specify How Fonts Degrade.
'-->!' inside the code is misleading and prompts a learner
to put the exclamation mark when it is not needed as '-->!' is
also followed by a period.
Instead of "'-->!'.", it should be "'-->'."
* Made text wording consistent for the test instructions.
* Changed "To begin with," to "To begin," and fixed a minor typo.
If we are going to use "To begin with," the sentence should be
"To begin with the lesson/challenge", otherwise, "To begin" will
be more than enough.
Also added a space between "font(using HTML..." and changed it to
"font (using HTML...".