julia: add page (#1089)

Based on the [man page](https://github.com/JuliaLang/julia/blob/master/doc/man/julia.1), and on the
[Getting started](https://github.com/JuliaLang/julia/blob/master/doc/manual/getting-started.rst) manual page.

pages/common/julia.md

@@ -0,0 +1,27 @@
+# julia
+
+> A high-level, high-performance dynamic programming language for technical computing.
+
+- Start a Julia REPL session:
+
+`julia`
+
+- Execute a Julia program and exit:
+
+`julia {{program.jl}}`
+
+- Execute a Julia program that takes arguments:
+
+`julia {{program.jl}} {{arguments}}`
+
+- Evaluate a string containing Julia code:
+
+`julia -e '{{julia_code}}'`
+
+- Evaluate a string of Julia code, passing arguments to it:
+
+`julia -e '{{for x in ARGS; println(x); end}}' {{arguments}}`
+
+- Start Julia in parallel mode, using N worker processes:
+
+`julia -p {{N}}`