add build dir and change name

.github/workflows/cmake-multi-linux.yml

@@ -1,6 +1,6 @@
 # This starter workflow is for a CMake project running on multiple platforms. There is a different starter workflow if you just want a single platform.
 # See: https://github.com/actions/starter-workflows/blob/main/ci/cmake-single-platform.yml
-name: CMake on multiple platforms
+name: linux gcc + clang
 
 on:
   push:
@@ -37,6 +37,14 @@ jobs:
     steps:
     - uses: actions/checkout@v3
 
+
+    - name: Set reusable strings
+      # Turn repeated input strings (such as the build output directory) into step outputs. These step outputs can be used throughout the workflow file.
+      id: strings
+      shell: bash
+      run: |
+        echo "build-output-dir=${{ github.workspace }}/build" >> "$GITHUB_OUTPUT"
+
 
     # - name: setup nasm windows
     #   if: runner.os == 'Windows'