chore: template README version and sha

Author: rcarcasses

README.md

@@ -19,7 +19,7 @@
        module_name = "rules_sbom",
        urls = ["https://github.com/rtbot-dev/rules_sbom/archive/refs/tags/v0.5.0.tar.gz"],
        strip_prefix = "rules_sbom-0.5.0",
-       sha256 = "<sha256>",
+       sha256 = "b0bed1fc15a1a782d0b971e960d1c04cd4fd3c84a4862198105a51e02622983e",
    )
    ```
    Update the version and checksum whenever you move to a newer release.

release-please-config.json

@@ -25,6 +25,12 @@
           "path": "README.md",
           "search": "rules_sbom-[0-9.]+",
           "replace": "rules_sbom-{{version}}"
+        },
+        {
+          "type": "text",
+          "path": "README.md",
+          "search": "sha256 = \"[0-9a-f]+\"",
+          "replace": "sha256 = \"{{sha256}}\""
         }
       ]
     }