Creates a temporary kernel instance, executes one or more lines of code, and returns any outputs and execution messages.
Mainly intended for quick testing of kernels during development.
stencila kernels execute [OPTIONS] <NAME> <CODE>
# Execute Python code
stencila kernels execute python "print('Hello World')"
# Execute multi-line code with escaped newlines
stencila kernels execute python "x = 5\nprint(x * 2)"
# Execute code in a sandboxed environment
stencila kernels execute python "import os\nprint(os.environ)" --box
# Use the exec alias
stencila kernels exec r "print(mean(c(1,2,3,4,5)))"
