Add UTF-8 charset by default to head

[jimthedev]

Currently there is no charset added by default in the head. The problem is that if you don't have are charset and use a UTF-8 font like any of those in Google Fonts then you can easily run into this problem.

[nkzawa]

SGTM

[nkzawa]

Related: #248

[rauchg]

+1 as well

[rauchg]

I'd still like to retain its customizability. We can basically have Head render a default utf-8 charset if none have been set. If <meta charSet> is passed, it overrides the default

[rauchg]

Also, isn't this fixed by sending the right encoding with the HTTP response?

[mikecardwell]

@rauchg - HTTP response headers are OK until the user goes and saves the HTML page to disk. When they open the document later in the same or a different browser, it will not know the charset unless it is embedded in the document.