Enable linting for the lint plugins

.eslintrc.json

@@ -24,7 +24,8 @@
       "parserOptions": {
         "project": [
           "./tsconfig.json",
-          "./cypress/tsconfig.json"
+          "./cypress/tsconfig.json",
+          "./lint/tsconfig.json"
         ],
         "createDefaultProgram": true
       },

angular.json

@@ -267,6 +267,7 @@
             "lintFilePatterns": [
               "src/**/*.ts",
               "cypress/**/*.ts",
+              "lint/**/*.ts",
               "src/**/*.html",
               "src/**/*.json5"
             ]