add HEAD for healthcheck

.gitignore

@@ -21,6 +21,7 @@ coverage
 .vscode/*
 !.vscode/extensions.json
 .idea
+.bsp/
 *.suo
 *.ntvs*
 *.njsproj

shotgun/.bsp/sbt.json

@@ -1 +0,0 @@
-{"name":"sbt","version":"1.9.1","bspVersion":"2.1.0-M1","languages":["scala"],"argv":["/Users/willfreeman/Library/Caches/Coursier/arc/https/github.com/adoptium/temurin17-binaries/releases/download/jdk-17.0.10%252B7/OpenJDK17U-jdk_x64_mac_hotspot_17.0.10_7.tar.gz/jdk-17.0.10+7/Contents/Home/bin/java","-Xms100m","-Xmx100m","-classpath","/Users/willfreeman/Library/Caches/Coursier/arc/https/github.com/sbt/sbt/releases/download/v1.8.2/sbt-1.8.2.zip/sbt/bin/sbt-launch.jar","-Dsbt.script=/Users/willfreeman/Library/Caches/Coursier/arc/https/github.com/sbt/sbt/releases/download/v1.8.2/sbt-1.8.2.zip/sbt/bin/sbt","xsbt.boot.Boot","-bsp"]}

shotgun/src/main/scala/me/deflock/shotgun/ShotgunServer.scala

@@ -83,6 +83,9 @@ object ShotgunServer {
           get {
             complete(HttpResponse(StatusCodes.OK, entity = "Service is healthy"))
           }
+          head {
+            complete(StatusCodes.OK)
+          }
         }
       )
     }