Add initial changelog for v2.065.

This is initial work, I suggest merging it first and then others can continue adding pulls when necessary. There doesn't seem to be a lot of new enhancements from what I can tell (or maybe they're not all in bugzilla).

**Note**: The list of all changes is based off of bugzilla and it may not reflect what's in the 2.065 branch. Some entries might have to be removed. We'll need to enhance the **changed.d** tool to take branches into account.

Also, one of these days we'll have to split this large page up into multiple pages. But we should do it while making sure the old hyperlinks still work, e.g. `dlang.org/changelog.html#d_scripts` would have to redirect to `dlang.org/changelog/2065.html#d_scripts` or something like that.

I'm scheduled to go away soon and I'll be back in a couple of weeks, so I likely won't be around for the release, or to amend this pull request. Cya!