Update HTML creating functions to preserve reserved characters

[allenbaron]

HTML reserved characters are listed at https://www.html.am/reference/html-special-characters.cfm and should be converted to proper HTML when updating resources on the Use Cases page or creating other html text.

Not sure how the " and ' are handled by babel. Need to look into this.

[allenbaron]

The reserved characters may be a more limited set (see https://stackoverflow.com/a/10371699/6938922), so using HTML for the " and ' may not matter for HTML. The " will matter inside of text marked for translation with babel (because " must be escaped in those cases).

Right now, I don't think DO.utils generates any text that ends up being translated by babel, so implementing conversion of " is likely not necessary.