Add build scaffolding for GHA and issue templates for GH

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,8 @@
+---
+name: Bug report
+about: Create a report to help us improve
+title: ''
+labels: bug
+assignees: ''
+
+---

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,5 @@
+blank_issues_enabled: false
+contact_links:
+  - name: Help and support
+    url: https://github.com/zeux/meshoptimizer/discussions
+    about: Please use GitHub Discussions if you have questions or need help.

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,8 @@
+---
+name: Feature request
+about: Suggest an idea for this project
+title: ''
+labels: enhancement
+assignees: ''
+
+---

.github/workflows/build.yml

@@ -0,0 +1,75 @@
+name: build
+
+on:
+  push:
+    branches:
+      - 'master'
+  pull_request:
+    paths-ignore:
+      - 'docs/**'
+      - 'papers/**'
+      - 'rfcs/**'
+      - '*.md'
+
+jobs:
+  unix:
+    strategy:
+      matrix:
+        os: [ubuntu, macos]
+    name: ${{matrix.os}}
+    runs-on: ${{matrix.os}}-latest
+    steps:
+    - uses: actions/checkout@v1
+    - name: make test
+      run: |
+        make -j2 config=sanitize test
+    - name: make test w/flags
+      run: |
+        make -j2 config=sanitize flags=true test
+    - name: make cli
+      run: |
+         make -j2 config=sanitize luau luau-analyze # match config with tests to improve build time
+         ./luau tests/conformance/assert.lua
+         ./luau-analyze tests/conformance/assert.lua
+
+  windows:
+    runs-on: windows-latest
+    strategy:
+      matrix:
+        arch: [Win32, x64]
+    steps:
+    - uses: actions/checkout@v1
+    - name: cmake configure
+      run: cmake . -A ${{matrix.arch}}
+    - name: cmake test
+      shell: bash # necessary for fail-fast
+      run: |
+        cmake --build . --target Luau.UnitTest Luau.Conformance --config Debug
+        Debug/Luau.UnitTest.exe
+        Debug/Luau.Conformance.exe
+    - name: cmake test w/flags
+      shell: bash # necessary for fail-fast
+      run: |
+        Debug/Luau.UnitTest.exe --fflags=true
+        Debug/Luau.Conformance.exe --fflags=true
+    - name: cmake cli
+      shell: bash # necessary for fail-fast
+      run: |
+        cmake --build . --target Luau.Repl.CLI Luau.Analyze.CLI --config Debug # match config with tests to improve build time
+        Debug/luau tests/conformance/assert.lua
+        Debug/luau-analyze tests/conformance/assert.lua
+
+  coverage:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v1
+    - name: install
+      run: |
+        sudo apt install llvm
+    - name: make coverage
+      run: |
+        CXX=clang++-10 make -j2 config=coverage coverage
+    - uses: actions/upload-artifact@v2
+      with:
+        name: coverage
+        path: coverage

.github/workflows/release.yml

@@ -0,0 +1,34 @@
+name: release
+
+on:
+  push:
+    branches:
+      - 'master'
+    paths-ignore:
+      - 'docs/**'
+      - 'papers/**'
+      - 'rfcs/**'
+
+jobs:
+  build:
+    strategy:
+      matrix:
+        os: [ubuntu, macos, windows]
+    name: ${{matrix.os}}
+    runs-on: ${{matrix.os}}-latest
+    steps:
+    - uses: actions/checkout@v1
+    - name: configure
+      run: cmake . -DCMAKE_BUILD_TYPE=Release
+    - name: build
+      run: cmake --build . --target Luau.Repl.CLI Luau.Analyze.CLI --config Release
+    - uses: actions/upload-artifact@v2
+      if: matrix.os != 'windows'
+      with:
+        name: luau-${{matrix.os}}
+        path: luau*
+    - uses: actions/upload-artifact@v2
+      if: matrix.os == 'windows'
+      with:
+        name: luau-${{matrix.os}}
+        path: Release\luau*.exe