chore(example): add flutter_lints for dart analysis

This resolves the issue on jetbrains IDEs where the dart analyzer doesn't start up nor the linting, intentions and auto-complete features.

Author: abdelhamid-f-nasser

example/analysis_options.yaml

@@ -0,0 +1,28 @@
+# This file configures the analyzer, which statically analyzes Dart code to
+# check for errors, warnings, and lints.
+#
+# The issues identified by the analyzer are surfaced in the UI of Dart-enabled
+# IDEs (https://dart.dev/tools#ides-and-editors). The analyzer can also be
+# invoked from the command line by running `flutter analyze`.
+
+# The following line activates a set of recommended lints for Flutter apps,
+# packages, and plugins designed to encourage good coding practices.
+include: package:flutter_lints/flutter.yaml
+
+linter:
+  # The lint rules applied to this project can be customized in the
+  # section below to disable rules from the `package:flutter_lints/flutter.yaml`
+  # included above or to enable additional rules. A list of all available lints
+  # and their documentation is published at https://dart.dev/lints.
+  #
+  # Instead of disabling a lint rule for the entire project in the
+  # section below, it can also be suppressed for a single line of code
+  # or a specific dart file by using the `// ignore: name_of_lint` and
+  # `// ignore_for_file: name_of_lint` syntax on the line or in the file
+  # producing the lint.
+  rules:
+    # avoid_print: false  # Uncomment to disable the `avoid_print` rule
+    # prefer_single_quotes: true  # Uncomment to enable the `prefer_single_quotes` rule
+
+# Additional information about this file can be found at
+# https://dart.dev/guides/language/analysis-options

example/pubspec.lock

@@ -75,6 +75,14 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
+  flutter_lints:
+    dependency: "direct dev"
+    description:
+      name: flutter_lints
+      sha256: b543301ad291598523947dc534aaddc5aaad597b709d2426d3a0e0d44c5cb493
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.0.4"
   flutter_test:
     dependency: "direct dev"
     description: flutter
@@ -92,6 +100,14 @@ packages:
       relative: true
     source: path
     version: "12.5.0"
+  lints:
+    dependency: transitive
+    description:
+      name: lints
+      sha256: a2c3d198cb5ea2e179926622d433331d8b58374ab8f29cdda6e863bd62fd369c
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.0.1"
   matcher:
     dependency: transitive
     description:

example/pubspec.yaml

@@ -32,6 +32,7 @@ dev_dependencies:
     sdk: flutter
   flutter_test:
     sdk: flutter
+  flutter_lints: 1.0.4
 
 # For information on the generic Dart part of this file, see the
 # following page: https://dart.dev/tools/pub/pubspec