HBASE-29659 Use webjar for bootswatch

instead of downloading it from a URL. We prefer maven resource as it can be cached locally.

Author: PDavid

pom.xml

@@ -2862,6 +2862,12 @@
                   <version>${site.bootstrap.version}</version>
                   <includes>**/js/bootstrap.min.js</includes>
                 </artifactItem>
+                <artifactItem>
+                  <groupId>org.webjars.npm</groupId>
+                  <artifactId>bootswatch</artifactId>
+                  <version>${site.bootswatch.version}</version>
+                  <includes>**/litera/bootstrap.min.css</includes>
+                </artifactItem>
                 <artifactItem>
                   <groupId>org.webjars</groupId>
                   <artifactId>popper.js</artifactId>
@@ -2892,25 +2898,6 @@
           </execution>
         </executions>
       </plugin>
-      <plugin>
-        <groupId>com.googlecode.maven-download-plugin</groupId>
-        <artifactId>download-maven-plugin</artifactId>
-        <version>${maven-download-plugin.version}</version>
-        <executions>
-          <execution>
-            <id>download-litera-bootstrap-theme</id>
-            <goals>
-              <goal>wget</goal>
-            </goals>
-            <phase>pre-site</phase>
-            <configuration>
-              <url>https://stackpath.bootstrapcdn.com/bootswatch/${site.bootswatch.version}/litera/bootstrap.min.css</url>
-              <outputDirectory>${project.build.directory}/site/css/themes/litera</outputDirectory>
-              <outputFileName>bootstrap.min.css</outputFileName>
-            </configuration>
-          </execution>
-        </executions>
-      </plugin>
       <!-- Special configuration for spotbugs just in the parent so
       the filter file location can be more general (see definition in pluginManagement) -->
       <plugin>
@@ -3073,6 +3060,13 @@
                     <include>bootstrap.min.js</include>
                   </includes>
                 </resource>
+                <resource>
+                  <directory>${project.build.directory}/META-INF/resources/webjars/bootswatch/${site.bootswatch.version}/dist/litera</directory>
+                  <targetPath>${project.build.directory}/site/css/themes/litera</targetPath>
+                  <includes>
+                    <include>bootstrap.min.css</include>
+                  </includes>
+                </resource>
                 <resource>
                   <directory>${project.build.directory}/META-INF/resources/webjars/popper.js/${site.popperjs.version}/umd</directory>
                   <targetPath>${project.build.directory}/site/js</targetPath>