Update mdoc, sbt-mdoc to 2.8.0 (#2695)

Author: softwaremill-ci

project/plugins.sbt

@@ -9,7 +9,7 @@ addSbtPlugin("com.softwaremill.sbt-softwaremill" % "sbt-softwaremill-common" % s
 addSbtPlugin("com.softwaremill.sbt-softwaremill" % "sbt-softwaremill-publish" % sbtSoftwareMillVersion)
 addSbtPlugin("com.softwaremill.sbt-softwaremill" % "sbt-softwaremill-browser-test-js" % sbtSoftwareMillVersion)
 
-addSbtPlugin("org.scalameta" % "sbt-mdoc" % "2.7.2")
+addSbtPlugin("org.scalameta" % "sbt-mdoc" % "2.8.0")
 
 addSbtPlugin("org.jetbrains.scala" % "sbt-ide-settings" % "1.1.3")
 addSbtPlugin("com.typesafe" % "sbt-mima-plugin" % "1.1.4")