Fill in scheme priorities

Author: ctrueden

src/main/java/org/apposed/appose/scheme/EnvironmentYmlScheme.java

@@ -45,8 +45,8 @@ public String name() {
 
 	@Override
 	public double priority() {
-		// TODO
-		return 0;
+		// Higher priority than requirements.txt, but lower than pixi.toml and pyproject.toml.
+		return 20;
 	}
 
 	@Override

src/main/java/org/apposed/appose/scheme/PixiTomlScheme.java

@@ -48,7 +48,7 @@ public String name() {
 
 	@Override
 	public double priority() {
-		// Lower priority than pyproject.toml but higher than plain text.
+		// Lower priority than pyproject.toml but higher than environment.yml and plain text.
 		return 50;
 	}
 

src/main/java/org/apposed/appose/scheme/RequirementsTxtScheme.java

@@ -48,7 +48,7 @@ public String name() {
 
 	@Override
 	public double priority() {
-		// TODO
+		// This scheme is less rich than the others, so don't prefer it.
 		return 0;
 	}