Adds comment to HASHTAGS_PATTERN

app/src/main/java/org/schabi/newpipe/util/external_communication/TextLinkifier.java

@@ -33,8 +33,9 @@ import static org.schabi.newpipe.util.external_communication.InternalUrlsHandler
 public final class TextLinkifier {
     public static final String TAG = TextLinkifier.class.getSimpleName();
 
+    // Looks for hashtags with characters from any language (\p{L}), numbers, or underscores
     private static final Pattern HASHTAGS_PATTERN =
-            Pattern.compile("(#[A-Za-z0-9_\\u0080-\\uFFFF]+)");
+            Pattern.compile("(#[\\p{L}0-9_]+)");
 
     private TextLinkifier() {
     }