Add GitHub annotations if running from GitHub Actions (#2)

* Add warnings

* Don't include github annotations if not using gha

Sources/SwiftPolyglot/main.swift

@@ -5,6 +5,7 @@ guard CommandLine.arguments.count > 1 else {
 	exit(1)
 }
 
+let isRunningFromGitHubActions = ProcessInfo.processInfo.environment["GITHUB_ACTIONS"] == "true"
 let languages = CommandLine.arguments[1].split(separator: ",").map(String.init)
 let errorOnMissing = CommandLine.arguments.contains("--errorOnMissing")
 
@@ -19,13 +20,17 @@ func checkTranslations(in fileURL: URL, for languages: [String]) {
 	      let jsonDict = jsonObject as? [String: Any],
 	      let strings = jsonDict["strings"] as? [String: [String: Any]]
 	else {
-		print("Could not process file: \(fileURL.path)")
+		if isRunningFromGitHubActions {
+			print("::warning file=\(fileURL.path)::Could not process file at path: \(fileURL.path)")
+		} else {
+			print("Could not process file at path: \(fileURL.path)")
+		}
 		return
 	}
 
 	for (originalString, translations) in strings {
 		guard let localizations = translations["localizations"] as? [String: [String: Any]] else {
-			print("Warning: '\(originalString)' is not translated in any language in file: \(fileURL.absoluteString)")
+			logWarning(file: fileURL.path, message: "'\(originalString)' is not translated in any language in file: \(fileURL.path)")
 			missingTranslations = true
 			continue
 		}
@@ -36,7 +41,7 @@ func checkTranslations(in fileURL: URL, for languages: [String]) {
 			   let state = stringUnit["state"] as? String, state == "translated"
 			{
 			} else {
-				print("Warning: '\(originalString)' is missing or not translated in \(lang) in file: \(fileURL.absoluteString)")
+				logWarning(file: fileURL.path, message: "'\(originalString)' is missing or not translated in \(lang) in file: \(fileURL.path)")
 				missingTranslations = true
 			}
 		}
@@ -54,6 +59,18 @@ func searchDirectory(_ dirPath: String) {
 	}
 }
 
+func logWarning(file: String, message: String) {
+	if isRunningFromGitHubActions {
+		if errorOnMissing {
+			print("::error file=\(file)::\(message)")
+		} else {
+			print("::warning file=\(file)::\(message)")
+		}
+	} else {
+		print(message)
+	}
+}
+
 searchDirectory(currentDirectoryPath)
 
 if missingTranslations, errorOnMissing {