Move Chipyard CI to Github Actions

- As similar as possible to the circle ci code.
- The `.github/README.md` file has a fair amount of documentation for this.
- Creates a worfklow file
  - re-uses most of the circleci/scipts unchanged
  - defines a number of *Composite Actions* which are like YML subroutines
- Removes the circle-ci code
- Points the CI badge in the top level README to use the GA test result

.github/actions/run-tests/action.yml

@@ -2,6 +2,13 @@ name: run-tests
 description: 'Runs tests according to input parameters'
 
 inputs:
+<<<<<<< HEAD
+=======
+  tools-version:
+    description: Which toolchain to build
+    required: false
+    default: 'riscv-tools'
+>>>>>>> 52c752ba... Move Chipyard CI to Github Actions
   group-key:
     description: group key
     required: true
@@ -16,6 +23,7 @@ inputs:
 runs:
   using: "composite"
   steps:
+<<<<<<< HEAD
     - name: Init submodules (since only the RTL is cached)
       run: ./scripts/init-submodules-no-riscv-tools.sh
       shell: bash
@@ -29,3 +37,13 @@ runs:
     - name: Run RTL tests
       run: ./.github/scripts/${{ inputs.run-script }} ${{ inputs.project-key }}
       shell: bash
+=======
+    - name: run rtl build script cache of chipyard root should have been loaded by prepare-rtl
+      run: |
+        export RISCV="/__w/chipyard/chipyard/riscv-tools-install"
+        export LD_LIBRARY_PATH="$RISCV/lib"
+        export PATH="$RISCV/bin:$PATH"
+        ./.github/scripts/${{ inputs.run-script }} ${{ inputs.project-key }}
+      shell: bash
+
+>>>>>>> 52c752ba... Move Chipyard CI to Github Actions