Update compatibility matrix (#4)

Author: github-actions[bot]

README.md

@@ -72,18 +72,15 @@ These are made available to subsequent workflow steps via the [`GITHUB_ENV` envi
 Support for the GCC toolchain varies across GitHub-hosted runner images.
 
 <!-- compat starts -->
-
-|                               | 5       | 6       | 7       | 8       | 9       | 10      | 11      | 12      |
-|-------------------------------|---------|---------|---------|---------|---------|---------|---------|---------|
-| ubuntu-22.04                  |         |         |         |         | &check; | &check; | &check; | &check; |
-| ubuntu-20.04 (ubuntu-latest)  |         |         | &check; | &check; | &check; | &check; | &check; |         |
-| ubuntu-18.04                  | &check; | &check; | &check; | &check; | &check; | &check; | &check; |         |
-| macos-12                      |         | &check; | &check; | &check; | &check; | &check; | &check; | &check; |
-| macos-11 (macos-latest)       |         | &check; | &check; | &check; | &check; | &check; | &check; | &check; |
-| macos-10.15                   |         | &check; | &check; | &check; | &check; | &check; | &check; | &check; |
-| windows-2022 (windows-latest) |         |         |         | &check; | &check; | &check; | &check; | &check; |
-| windows-2019                  |         |         |         | &check; | &check; | &check; | &check; | &check; |
-
+| runner       | 5       | 6       | 7       | 8       | 9       | 10      | 11      | 12      |
+|:-------------|:--------|:--------|:--------|:--------|:--------|:--------|:--------|:--------|
+| macos-11     |      | &check; | &check; | &check; | &check; | &check; | &check; | &check; |
+| macos-12     |      | &check; | &check; | &check; | &check; | &check; | &check; | &check; |
+| ubuntu-18.04 | &check; | &check; | &check; | &check; | &check; | &check; | &check; |      |
+| ubuntu-20.04 |      |      | &check; | &check; | &check; | &check; | &check; |      |
+| ubuntu-22.04 |      |      |      |      | &check; | &check; | &check; | &check; |
+| windows-2019 |      |      |      | &check; | &check; | &check; | &check; | &check; |
+| windows-2022 |      |      |      | &check; | &check; | &check; | &check; | &check; |
 <!-- compat ends -->
 
 

compat.csv

@@ -0,0 +1,8 @@
+runner,5,6,7,8,9,10,11,12
+macos-11,,✓,✓,✓,✓,✓,✓,✓
+macos-12,,✓,✓,✓,✓,✓,✓,✓
+ubuntu-18.04,✓,✓,✓,✓,✓,✓,✓,
+ubuntu-20.04,,,✓,✓,✓,✓,✓,
+ubuntu-22.04,,,,,✓,✓,✓,✓
+windows-2019,,,,✓,✓,✓,✓,✓
+windows-2022,,,,✓,✓,✓,✓,✓