Remove relative path to vendored shards markd and reply (#13992)

Author: nobodywasishere

src/compiler/crystal/interpreter/repl_reader.cr

@@ -1,4 +1,4 @@
-require "../../../../lib/reply/src/reply"
+require "reply"
 
 class Crystal::ReplReader < Reply::Reader
   KEYWORDS = %w(

src/compiler/crystal/tools/doc/generator.cr

@@ -1,4 +1,4 @@
-require "../../../../../lib/markd/src/markd"
+require "markd"
 require "crystal/syntax_highlighter/html"
 
 class Crystal::Doc::Generator

src/compiler/crystal/tools/playground/server.cr

@@ -2,7 +2,7 @@ require "http/server"
 require "log"
 require "ecr/macros"
 require "compiler/crystal/tools/formatter"
-require "../../../../../lib/markd/src/markd"
+require "markd"
 
 module Crystal::Playground
   Log = ::Log.for("crystal.playground")