Deprecate .Site.Sites.First in favor of .Site.Sites.Default

[jmooring]

Prior to v0.123.0, .Site.Sites returned the sites sorted by weight then language key. With v0.123.0 and later, the site corresponding to the default language is first on the list.

With this config...

defaultContentLanguage = 'de'

[languages.en]
weight = 1

[languages.de]
weight = 2

[languages.fr]
weight = 3

....Site.Sites.First now returns the second site, which is exactly what it should be doing. But I think we should rename the method to describe what it does.

If implemented, need to update:

• https://gohugo.io/methods/page/sites/
• https://gohugo.io/methods/site/sites/