Make XP project page the canonical truth for excerpt on landing page

Every JUnit Pioneer project (at the moment, just XP) has its own
project page with its own header inclduing the group ID, project ID,
and version. The landing page displays the excerpt of one such
project. Before this change, the ecerpts was duplicated in two files
and needed to be kept in sync manually.

Now, the landing page's expert is pulled from the XP project page.

Related to #9

Author: Nicolai Parlog

build.gradle

@@ -61,18 +61,18 @@ task removeDocNav() {
 	}
 }
 
-task removeVersion() {
+task removeXpFromHome {
 	doLast {
-		description 'Removes current version from site-source/_pages/home.md'
+		description 'Removes XP excerpt from _site-source/_pages/home.md'
 		File home = file('site-source/_pages/home.md')
 		String homeText = home.getText()
-		String homeTextWithVersion = homeText.replaceAll(/`org.junit-pioneer : junit-pioneer : [^`]*`/, "`org.junit-pioneer : junit-pioneer : @xp:version`")
-		home.setText(homeTextWithVersion)
+		String homeTextWithoutXpExcerpt = homeText.replaceAll(/(?m)^excerpt: .*/, "excerpt: @xp:excerpt")
+		home.setText(homeTextWithoutXpExcerpt)
 	}
 }
 
 task clean {
-	dependsOn removeProjectPage, removeDocs, removeDocNav, removeVersion
+	dependsOn removeProjectPage, removeDocs, removeDocNav, removeXpFromHome
 }
 
 // ------
@@ -82,7 +82,7 @@ task clean {
 task copyProjectPage(type: Copy) {
 	from 'junit-pioneer/docs/'
 	include 'project-page.*'
-	rename 'project-page.(.*)', 'xp.$1'
+	rename 'project-page.adoc', 'xp.adoc'
 	into 'site-source/_pages'
 }
 
@@ -104,20 +104,34 @@ task insertDocNav() {
 }
 
 task insertVersion() {
+	dependsOn copyProjectPage
 	doLast {
-		description 'Inserts current XP version into site-source/_pages/home.md'
+		description 'Inserts current XP version into XP about page'
 		Properties properties = new Properties()
 		file('junit-pioneer/version.properties').withInputStream { properties.load(it) }
 		String version = properties.previousVersion
+		File aboutXp = file('site-source/_pages/xp.adoc')
+		String aboutXpText = aboutXp.getText()
+		String aboutXpTextWithVersion = aboutXpText.replaceAll(/@xp:version/, version)
+		aboutXp.setText(aboutXpTextWithVersion)
+	}
+}
+
+task insertXpIntoHome() {
+	dependsOn insertVersion
+	doLast {
+		description 'Inserts XP excerpt into _site-source/_pages/home.md'
+		String xpContent = file('site-source/_pages/xp.adoc').getText()
+		String excerpt = xpContent.find(/excerpt: .*/)
 		File home = file('site-source/_pages/home.md')
 		String homeText = home.getText()
-		String homeTextWithVersion = homeText.replaceAll(/@xp:version/, "${version}")
-		home.setText(homeTextWithVersion)
+		String homeTextWithXpExcerpt = homeText.replaceAll(/(?m)^excerpt: @xp:excerpt/, excerpt)
+		home.setText(homeTextWithXpExcerpt)
 	}
 }
 
 task create {
-	dependsOn copyProjectPage, copyDocs, insertDocNav, insertVersion
+	dependsOn copyProjectPage, copyDocs, insertDocNav, insertVersion, insertXpIntoHome
 }
 
 // -----