fix(startup): Make "Upgrade the sheet" less confusing

fixes #469

lib/entry-point.js

@@ -90,8 +90,9 @@ function runStartup(character, retryCount) {
   logger.info('Detected sheet version as : $$$', version);
 
   if (Utils.versionCompare(version, MINIMUM_SHEET_VERSION) < 0) {
-    const error = `Incompatible sheet version ${version}. You need at least version ${MINIMUM_SHEET_VERSION} to ` +
-      'use this script. Please install an updated sheet.';
+    const error = `The Shaped companion script requires the Shaped sheet to be version ${MINIMUM_SHEET_VERSION} ` +
+      `or higher. You're currently using version ${version}. Please install the latest Shaped sheet from github: ` +
+      'https://github.com/mlenser/roll20-character-sheets/tree/master/5eShaped';
     reporter.reportError(error);
     logger.error(error);
     commandProc.setDefaultCommandHandler(() => reporter.reportError(error));