docs: link the compiler fork and project repositories

README.md

@@ -13,6 +13,20 @@ clients are M1–M5 and are separate plans (see the design spec).
 - Spike: [`spike/REPORT-23.md`](spike/REPORT-23.md) (current, LLVM 23.1.5);
   [`spike/REPORT.md`](spike/REPORT.md) (historical, 19.1.7)
 
+## Repositories
+
+- **Compiler fork:** <https://git.wut.ee/opencode.siil.arti.ee/llvm-tms34010>
+  (branch `tms34010`) — the full buildable LLVM 23.1.5 tree with the TMS34010
+  target and clang bit-address changes.
+- **This project:** <https://git.wut.ee/opencode.siil.arti.ee/tms-c-compiler>
+  — plans/specs, VT1200 integration tooling, `tms-bitaddr`, `tms-clang`,
+  symbols and the spike.
+
+The compiler fork is the canonical source for LLVM changes. `patches/llvm`
+here is a lightweight mirror used by `scripts/build-llvm.sh`, so the project
+can be built without cloning 3 GB of LLVM; keep it in sync with the fork's
+`tms34010` branch.
+
 ## What M0 provides
 
 - `clang --target=tms34010-unknown-none`: 32-bit bit-addressed pointers,