Update sbt-microsites to 1.3.3

Author: 47erbot

project/plugins.sbt

@@ -1,5 +1,5 @@
 addSbtPlugin("com.geirsson"              % "sbt-ci-release"           % "1.5.7")
-addSbtPlugin("com.47deg"                 % "sbt-microsites"           % "1.3.2")
+addSbtPlugin("com.47deg"                 % "sbt-microsites"           % "1.3.3")
 addSbtPlugin("org.scoverage"             % "sbt-scoverage"            % "1.6.1")
 addSbtPlugin("org.scalameta"             % "sbt-scalafmt"             % "2.4.2")
 addSbtPlugin("org.scalameta"             % "sbt-mdoc"                 % "2.2.19")