Update cheatsheets

ruby

@@ -0,0 +1,34 @@
+---
+syntax: markdown
+tags: [tldr, common]
+source: https://github.com/tldr-pages/tldr.git
+---
+# ruby
+
+> Ruby programming language interpreter.
+> See also: `gem`, `bundler`, `rake`, `irb`.
+> More information: <https://www.ruby-lang.org>.
+
+- Execute a Ruby script:
+
+`ruby {{script.rb}}`
+
+- Execute a single Ruby command in the command-line:
+
+`ruby -e {{command}}`
+
+- Check for syntax errors on a given Ruby script:
+
+`ruby -c {{script.rb}}`
+
+- Start the built-in HTTP server on port 8080 in the current directory:
+
+`ruby -run -e httpd`
+
+- Locally execute a Ruby binary without installing the required library it depends on:
+
+`ruby -I {{path/to/library_folder}} -r {{library_require_name}} {{path/to/bin_folder/bin_name}}`
+
+- Display Ruby version:
+
+`ruby -v`