Media: drop the mp4 montage, use the GIF in README + Pages; remove orphan bug shots

- README and docs/index.md (Pages) now embed goldeneye-gh-preview.gif
  where the mp4 <video> tag was; release notes already used the GIF
- git rm the 27 MB mp4 (GIF stays — it is the release-notes asset, pinned
  to the v0.2.0 tag)
- remove three unreferenced docs/img/bugs screenshots left over from the
  culling/D176 A-B captures

README.md

@@ -30,10 +30,11 @@ See [Background](#background).
 
 <p align="center">
   <img src="docs/img/attract-bunker1.png" width="32%" alt="Bunker 1 intro camera">
-  <video src="docs/media/goldeneye-gh-preview.mp4" width="32%" controls muted loop></video>
+  <img src="docs/media/goldeneye-gh-preview.gif" width="32%"
+       alt="~32 s gameplay montage from live play sessions">
   <img src="docs/img/attract-dam.png" width="32%" alt="Dam intro camera">
   <br><em>In-engine, running in the port — Bunker&nbsp;1 and Dam attract views, and a
-  ~32&nbsp;s gameplay montage from live play sessions (the clip has no audio track).</em>
+  ~32&nbsp;s gameplay montage loop from live play sessions.</em>
 </p>
 
 ## Download

docs/index.md

@@ -24,8 +24,9 @@ handful of cosmetic rendering defects remain — are listed plainly under
 [Honest status](#honest-status).
 
 <p align="center">
-  <video src="media/goldeneye-gh-preview.mp4" width="70%" controls muted loop></video>
-  <br><em>~32 s gameplay montage from live play sessions, running in the port (the clip has no audio track).</em>
+  <img src="media/goldeneye-gh-preview.gif" width="70%"
+       alt="~32 s gameplay montage from live play sessions">
+  <br><em>~32 s gameplay montage loop from live play sessions, running in the port.</em>
 </p>
 
 ## Download