Make the rgoue branch Go-only

The port is complete, so the C sources and their build system
(autoconf/automake inputs, Makefiles, Visual Studio project, doc
templates, RPM spec, C build/modernization notes) leave this branch;
they live on in master/modern-rogue for reference.

Also ports the last missing wizard command (things.c pr_list/pr_spec,
the '*' item-probability listing), rewrites README.md for the Go port,
and updates ARCHITECTURE.md's layout notes (game/ has no third-party
imports; tcell lives in term/).

Kept: LICENSE.TXT, rogue.png, rogue.desktop, ARCHITECTURE.md.

ARCHITECTURE.md

@@ -924,9 +924,9 @@ Module: **`sneak.berlin/go/rogue`**
 
 ## 2. Repository and package layout
 
-The C sources remain in the repository root as the reference implementation.
-Go code lives in subdirectories (Go will not build a package directory that
-contains foreign `.c` files):
+The C reference implementation lives on the `master`/`modern-rogue`
+branches; this branch is Go-only. The tcell wrapper ended up in its own
+`term` package so that `game` itself has no third-party imports:
 
 ```
 go.mod                        module sneak.berlin/go/rogue