Name it Gyre - Sand Art Table

README, build guide, software README, web page header and title, jog page,
desktop alerts and the start-up message now say Gyre. The repo, the Python
package and its commands keep their names (sandTable, python3 -m sandtable),
so links and setups keep working. New web page screenshot.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

software/sandtable/__init__.py

@@ -1 +1 @@
-"""Sand table pattern player: .thr files and built-in patterns -> GRBL / FluidNC over USB."""
+"""Gyre sand art table: pattern player for .thr files and built-in patterns -> GRBL / FluidNC over USB."""