Update critical file(s) according to Chirpy v4.0.0

Gemfile

@@ -1,6 +1,6 @@
 source "https://rubygems.org"
 
-gem "jekyll-theme-chirpy", "~> 3.3"
+gem "jekyll-theme-chirpy", "~> 4.0", ">= 4.0.0"
 
 group :jekyll_plugins do
   # If you have any plugins, put them here!

_config.yml

@@ -50,15 +50,11 @@ google_site_verification: google_meta_tag_verification # change to your verifica
 # --------------------------
 
 google_analytics:
-  id: ''          # Fill with your Google Analytics ID
+  id: ''              # fill in your Google Analytics ID
+  # Google Analytics pageviews report settings
   pv:
-    # The Google Analytics pageviews switch.
-    # DO NOT enable it unless you know how to deploy the Google Analytics superProxy.
-    enabled: false
-    # the next options only valid when `google_analytics.pv` is enabled.
-    proxy_url: ''
-    proxy_endpoint: ''
-    cache: false  # pv data local cache, good for the users from GFW area.
+    proxy_endpoint:   # fill in the Google Analytics superProxy endpoint of Google App Engine
+    cache_path:       # the local PV cache data, friendly to visitors from GFW region
 
 # Prefer color scheme setting.
 #
@@ -105,10 +101,6 @@ kramdown:
       line_numbers: true
       start_line: 1
 
-# DO NOT change this unless you're a Pro user on Jekyll and Web development,
-# Or you think you're smart enough to change other relevant URLs within this template.
-permalink: /posts/:title/
-
 collections:
   tabs:
     output: true
@@ -124,6 +116,9 @@ defaults:
       layout: post
       comments: true    # Enable comments in posts.
       toc: true         # Display TOC column in posts.
+      # DO NOT modify the following parameter unless you are confident enough
+      # to update the code of all other post links in this project.
+      permalink: /posts/:title/
   -
     scope:
       path: _drafts
@@ -151,9 +146,6 @@ compress_html:
     envs: [development]
 
 exclude:
-  - vendor
-  - Gemfile
-  - Gemfile.lock
   - '*.gem'
   - '*.gemspec'
   - tools
@@ -162,8 +154,7 @@ exclude:
   - LICENSE
   - gulpfile.js
   - node_modules
-  - package.json
-  - package-lock.json
+  - '*.json'
 
 jekyll-archives:
   enabled: [categories, tags]