use pekko-sbt-paradox theme for docs (#156)

Fixes #153

build.sbt

@@ -248,6 +248,7 @@ lazy val docs = pekkoModule("docs")
   .settings(javacOptions += "-parameters") // for Jackson
   .enablePlugins(
     ParadoxPlugin,
+    PekkoParadoxPlugin,
     PublishRsyncPlugin,
     NoPublish,
     ParadoxBrowse,

project/Paradox.scala

@@ -17,6 +17,7 @@ import com.lightbend.paradox.sbt.ParadoxPlugin
 import com.lightbend.paradox.sbt.ParadoxPlugin.autoImport._
 import com.lightbend.paradox.apidoc.ApidocPlugin
 import com.lightbend.sbt.publishrsync.PublishRsyncPlugin.autoImport._
+import org.apache.pekko.PekkoParadoxPlugin.autoImport._
 import sbt.Keys._
 import sbt._
 
@@ -77,6 +78,11 @@ object Paradox {
       // TODO page not linked to
       "fault-tolerance-sample.html"))
 
+  val themeSettings = Seq(
+    // allow access to snapshots for pekko-sbt-paradox
+    resolvers += "Apache Nexus Snapshots".at("https://repository.apache.org/content/repositories/snapshots/"),
+    pekkoParadoxGithub := "https://github.com/apache/incubator-pekko")
+
   // FIXME https://github.com/lightbend/paradox/issues/350
   // Exclusions from direct compilation for includes dirs/files not belonging in a TOC
   val includesSettings = Seq(
@@ -97,6 +103,7 @@ object Paradox {
     includesSettings ++
     groupsSettings ++
     parsingSettings ++
+    themeSettings ++
     Seq(
       Compile / paradox / name := "Pekko",
       resolvers += Resolver.jcenterRepo,

project/plugins.sbt

@@ -15,11 +15,7 @@ addSbtPlugin("com.github.sbt" % "sbt-unidoc" % "0.5.0")
 addSbtPlugin("com.thoughtworks.sbt-api-mappings" % "sbt-api-mappings" % "3.0.2")
 addSbtPlugin("pl.project13.scala" % "sbt-jmh" % "0.4.3")
 addSbtPlugin("io.spray" % "sbt-boilerplate" % "0.6.1")
-// We have to deliberately use older versions of sbt-paradox because current Pekko sbt build
+
-// only loads on JDK 1.8 so we need to bring in older versions of parboiled which support JDK 1.8
-addSbtPlugin("com.lightbend.paradox" % "sbt-paradox" % "0.9.2")
-addSbtPlugin("com.lightbend.paradox" % "sbt-paradox-apidoc" % "0.10.1")
-addSbtPlugin("com.lightbend.paradox" % "sbt-paradox-project-info" % "2.0.0")
 addSbtPlugin("de.heikoseeberger" % "sbt-header" % "5.7.0")
 addSbtPlugin("com.hpe.sbt" % "sbt-pull-request-validator" % "1.0.0")
 addSbtPlugin("net.bzzt" % "sbt-reproducible-builds" % "0.30")
@@ -28,3 +24,16 @@ addSbtPlugin("com.github.sbt" % "sbt-ci-release" % "1.5.10")
 addSbtPlugin("com.lightbend.sbt" % "sbt-publish-rsync" % "0.2")
 addSbtPlugin("com.github.pjfanning" % "sbt-source-dist" % "0.1.2")
 addSbtPlugin("com.github.reibitto" % "sbt-welcome" % "0.2.2")
+
+// allow access to snapshots for pekko-sbt-paradox
+resolvers += "Apache Nexus Snapshots".at("https://repository.apache.org/content/repositories/snapshots/")
+
+// We have to deliberately use older versions of sbt-paradox because current Pekko sbt build
+// only loads on JDK 1.8 so we need to bring in older versions of parboiled which support JDK 1.8
+addSbtPlugin(("org.apache.pekko" % "pekko-sbt-paradox" % "0.0.0+19-f498f7c0-SNAPSHOT").excludeAll(
+  "com.lightbend.paradox", "sbt-paradox",
+  "com.lightbend.paradox" % "sbt-paradox-apidoc",
+  "com.lightbend.paradox" % "sbt-paradox-project-info"))
+addSbtPlugin(("com.lightbend.paradox" % "sbt-paradox" % "0.9.2").force())
+addSbtPlugin(("com.lightbend.paradox" % "sbt-paradox-apidoc" % "0.10.1").force())
+addSbtPlugin(("com.lightbend.paradox" % "sbt-paradox-project-info" % "2.0.0").force())