```
misc/freebsd-doc-*: Enable HTML in all languages
Several improvements with this change:
Make the HTML option default for all languages.
Non-English ports must build the HTML English version together, and the
shared files are stored in the freebsd-doc-en port.
Fix some image's src addresses on freebsd-doc-en.
Point MASTER_SITES to LOCAL/doceng; it's a shared folder with the team.
Use OPTIONS_MULTI; it's necessary to choose at least one DOC_FORMAT.
```