Remove placeholder comments

These aren't that useful. The link to the docs at the top of the file might be useful, though.

.devcontainer/devcontainer.json

@@ -2,7 +2,6 @@
 // README at: https://github.com/devcontainers/templates/tree/main/src/java
 {
 	"name": "Java",
-	// Or use a Dockerfile or Docker Compose file. More info: https://containers.dev/guide/dockerfile
 	"image": "mcr.microsoft.com/devcontainers/java:1-8-bullseye",
 
 	"features": {
@@ -12,16 +11,4 @@
 			"installGradle": "false"
 		}
 	}
-
-	// Use 'forwardPorts' to make a list of ports inside the container available locally.
-	// "forwardPorts": [],
-
-	// Use 'postCreateCommand' to run commands after the container is created.
-	// "postCreateCommand": "java -version",
-
-	// Configure tool-specific properties.
-	// "customizations": {},
-
-	// Uncomment to connect as root instead. More info: https://aka.ms/dev-containers-non-root.
-	// "remoteUser": "root"
 }