[FLINK-20832][docs] Deliver bootstrap css and js ourselves

This closes apache#14590

Author: wuchong

NOTICE

@@ -9,6 +9,15 @@ See bundled license files for details.
 
 - jQuery v3.5.1 | (c) JS Foundation and other contributors
 	-> in "docs/page/js/jquery.min.js"
+- AnchorJS v3.1.0 (https://github.com/bryanbraun/anchorjs) Copyright (c) 2016 Bryan Braun
+    -> in "docs/page/js/anchor.min.js"
+- Bootstrap v3.3.4 (http://getbootstrap.com) Copyright 2011-2015 Twitter, Inc.
+    -> css in "docs/page/css/bootstrap.min.css"
+    -> js in "docs/page/js/bootstrap.min.js"
+    -> fonts in "docs/page/fonts"
+
+Note: The "docs/page/fonts/glyphicons-halflings*" fonts are included in Bootstrap, and licensed under the same license as Boostrap.
+See https://glyphicons.com/old/license.html#old-halflings-bootstrap for more information.
 
 This project bundles the following dependencies under the BSD license.
 See bundled license files for details.
@@ -39,4 +48,3 @@ The Apache Flink project contains or reuses code that is licensed under the Apac
 - Google Cloud Client Library for Java (https://github.com/googleapis/google-cloud-java) Copyright 2017 Google LLC
 
   See: flink-end-to-end-tests/flink-connector-gcp-pubsub-emulator-tests/src/test/java/org/apache/flink/streaming/connectors/gcp/pubsub/emulator/PubsubHelper.java
-

docs/_layouts/base.html

@@ -29,7 +29,7 @@
     <link rel="canonical" href="{{ site.stable_baseurl }}{{ page.url | replace:'index.html',''}}">
 
     <!-- Bootstrap -->
-    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/css/bootstrap.min.css">
+    <link rel="stylesheet" href="{% link page/css/bootstrap.min.css %}">
     <link rel="stylesheet" href="{% link page/css/flink.css %}">
     <link rel="stylesheet" href="{% link page/css/syntax.css %}">
     <link rel="stylesheet" href="{% link page/css/codetabs.css %}">
@@ -91,8 +91,8 @@
     <!-- jQuery (necessary for Bootstrap's JavaScript plugins) -->
     <script src="{% link page/js/jquery.min.js %}"></script>
     <!-- Include all compiled plugins (below), or include individual files as needed -->
-    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/js/bootstrap.min.js"></script>
-    <script src="https://cdnjs.cloudflare.com/ajax/libs/anchor-js/3.1.0/anchor.min.js"></script>
+    <script src="{% link page/js/bootstrap.min.js %}"></script>
+    <script src="{% link page/js/anchor.min.js %}"></script>
     <script src="{% link page/js/flink.js %}"></script>
 
     <!-- Google Analytics -->

docs/page/css/bootstrap.min.css

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2020 Bryan Braun
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

docs/page/fonts/glyphicons-halflings-regular.eot

@@ -0,0 +1,22 @@
+The MIT License (MIT)
+
+Copyright (c) 2011-2021 Twitter, Inc.
+Copyright (c) 2011-2021 The Bootstrap Authors
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

docs/page/fonts/glyphicons-halflings-regular.svg

@@ -1408,9 +1408,11 @@ under the License.
 						<!-- External web libraries. -->
 						<exclude>docs/**/jquery*</exclude>
 						<exclude>docs/**/bootstrap*</exclude>
+						<exclude>docs/**/anchor*</exclude>
 						<exclude>docs/Gemfile.lock</exclude>
 						<exclude>docs/ruby2/Gemfile.lock</exclude>
 						<exclude>docs/img/*.svg</exclude>
+						<exclude>**/docs/page/fonts/**</exclude>
 						<exclude>**/docs/page/font-awesome/**</exclude>
 						<exclude>**/resources/**/font-awesome/**</exclude>
 						<exclude>**/resources/**/jquery*</exclude>