Update sbt-mdoc to 2.9.1 (#198)

Author: softwaremill-ci

project/plugins.sbt

@@ -2,6 +2,6 @@ val sbtSoftwareMillVersion = "2.1.2"
 
 addSbtPlugin("com.softwaremill.sbt-softwaremill" % "sbt-softwaremill-common" % sbtSoftwareMillVersion)
 addSbtPlugin("com.softwaremill.sbt-softwaremill" % "sbt-softwaremill-publish" % sbtSoftwareMillVersion)
-addSbtPlugin("org.scalameta" % "sbt-mdoc" % "2.9.0")
+addSbtPlugin("org.scalameta" % "sbt-mdoc" % "2.9.1")
 addSbtPlugin("io.spray" % "sbt-revolver" % "0.10.0")
 addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "2.3.1")