Update version and README version table (#809)

Author: NicolasHug

README.md

@@ -131,6 +131,7 @@ The following table indicates the compatibility between versions of
 | `torchcodec`       | `torch`            | Python              |
 | ------------------ | ------------------ | ------------------- |
 | `main` / `nightly` | `main` / `nightly` | `>=3.9`, `<=3.13`   |
+| `0.6`              | `2.8`              | `>=3.9`, `<=3.13`   |
 | `0.5`              | `2.7`              | `>=3.9`, `<=3.13`   |
 | `0.4`              | `2.7`              | `>=3.9`, `<=3.13`   |
 | `0.3`              | `2.7`              | `>=3.9`, `<=3.13`   |

version.txt

@@ -1 +1 @@
-0.6.0a0
+0.7.0a0