ci, build: replace CI workflows with thin wrappers

Splits the repository so C++ source stays on master and CI scripts,
docs, and examples move to the support branch. Master's CI workflows
become thin wrappers that delegate to the reusable workflows on the
support branch.

GitHub Actions changes:
- ci.yml, bitcoin-core-ci.yml: replaced with thin wrappers that call
  the corresponding reusable workflows on the support branch.

CMakeLists.txt:
- Remove add_subdirectory(example): example/ moves to the support
  branch and is built from support's own CMakeLists.txt.

README.md:
- Update documentation links to point to the support branch.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: ryanofsky

.github/workflows/bitcoin-core-ci.yml

@@ -0,0 +1,14 @@
+name: Bitcoin Core CI
+
+on:
+  push:
+  pull_request:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  bitcoin-core-ci:
+    uses: bitcoin-core/libmultiprocess/.github/workflows/bitcoin-core-ci.yml@support
+    secrets: inherit

.github/workflows/ci.yml

@@ -0,0 +1,10 @@
+name: CI
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  ci:
+    uses: bitcoin-core/libmultiprocess/.github/workflows/ci.yml@support
+    secrets: inherit

CMakeLists.txt

@@ -265,6 +265,4 @@ add_custom_target(install-lib
   VERBATIM)
 add_dependencies(install-lib multiprocess)
 
-# Example and test subdirectories
-add_subdirectory(example EXCLUDE_FROM_ALL)
 add_subdirectory(test EXCLUDE_FROM_ALL)

README.md

@@ -2,7 +2,11 @@
 
 `libmultiprocess` is a C++ library and code generator making it easy to call functions and reference objects in different processes.
 
-For more information see the [usage instructions](doc/usage.md), [installation instructions](doc/install.md), or [design documentation](doc/design.md).
+For more information see the [usage instructions](https://github.com/bitcoin-core/libmultiprocess/blob/support/doc/usage.md), [installation instructions](https://github.com/bitcoin-core/libmultiprocess/blob/support/doc/install.md), or [design documentation](https://github.com/bitcoin-core/libmultiprocess/blob/support/doc/design.md) in the [support branch](https://github.com/bitcoin-core/libmultiprocess/tree/support). In a local checkout, the following command will check out the support branch, which includes CI scripts, documentation, and examples, to a subdirectory called `support`:
+
+```bash
+git worktree add support
+```
 
 If you have any questions, comments, or feedback, please submit an [issue](https://github.com/bitcoin-core/libmultiprocess/issues/new).
 Duplicate issues are perfectly fine and all discussion about the project is welcome, since there isn't another discussion forum currently.