Bring the homepage headshot back into the repo

The Linode bucket added unnecessary indirection for a single small
static image. Commit will.jpg under static/images/ and point the
homepage at it directly; the now-orphaned copy has been deleted from
the reground-downloads bucket. The freebie PDF stays on
downloads.reground.org, unaffected.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

content/_index.md

@@ -3,7 +3,7 @@ title: "ReGround"
 description: "DevOps consulting, ghostwriting, and helping fiction authors find their right readers"
 ---
 
-![Will Estes](https://downloads.reground.org/will.jpg)
+![Will Estes](/images/will.jpg)
 
 ## Creative Help