Add julia-repl alias and document Julia aliases

Author: mortenpi

src/languages/julia.js

@@ -84,7 +84,25 @@ function(hljs) {
 
   // placeholder for recursive self-reference
   var DEFAULT = {
-    aliases: ['jldoctest'],
+    // The aliases here are placeholders for future grammars that incorporate Julia code.
+    // However, simply applying ordinary Julia highlighting is good enough for now.
+    //
+    // `julia-repl` should highlight interactive REPL code snippets. A REPL line starts with
+    // "julia>" and is followed by Julia code, which should be highlighted accordingly.
+    // Generally the code is a single Julia statement, which may also span multiple lines.
+    // The Julia code may then be followed by the output of the executed code and should not
+    // be highlighted. For example:
+    //
+    //     julia> function foo(x)
+    //       x + 1
+    //     end
+    //     foo (generic function with 1 method)                <-- should not be highlighted
+    //
+    // `jldoctest` Markdown blocks are used in the Julia manual and package docs indicate
+    // code snippets that should be verified when the documentation is built. They can be
+    // either REPL-type or script-type, and are documented in Documenter's manual:
+    // https://juliadocs.github.io/Documenter.jl/latest/man/doctests.html
+    aliases: ['jldoctest', 'julia-repl'],
     lexemes: VARIABLE_NAME_RE, keywords: KEYWORDS, illegal: /<\//
   };