Commentout

Single-line comments:
- Place the cursor on the line you want to comment out.
- Use the shortcut Command + / (on macOS) or Ctrl + / (on Windows/Linux).
Example:
```
# say = "I love Ruby"
# puts say
```
Multi-line comments:
- Select the block of code you want to comment out.
- Use the shortcut Option + Shift + A (on macOS) or Alt + Shift + A (on Windows/Linux).
Example:
```
=begin 
say['love'] = "*love*"
puts say.upcase
=end
```