Copy Babel resolver alias config to ESLint config

At the time of writing, eslint-import-resolver-babel-module does not
find the monorepo Babel configuration so the alias configuration must be
repeated in the ESLint configuration file.
diff --git a/.eslintrc.js b/.eslintrc.js
index 2b8a0d7..a82fcb9 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -38,7 +38,11 @@
   },
   settings: {
     'import/resolver': {
-      'babel-module': {},
+      'babel-module': {
+        alias: {
+          '^@annotator/(.+)$': '@annotator/\\1/src/index.js',
+        },
+      },
     },
   },
   overrides: [