Update README

Dependencies

• [2] HCY72TQR Improve linting
• [3] M5U5PAX7 Add wrapper script, improve libdemo
• [4] JGZ7GBCL Add linting
• [5] 7AUC4NKI Initial commit

Change contents

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  +

  + ## Requirements

  +

  + [Nix](https://nixos.org/download.html) with [flakes enabled](https://github.com/mschwaig/howto-install-nix-with-flake-support) must be available.

  +

  +

  + ## Usage

  +

  + Run all demos in order using

  +

  + ```console

  + $ ./demo-full.sh

  + ```

  +

  + or run one particular demo using `./<xx-demo-name>/demo.sh`.

  +

  + Available options:

  +

  + ```console

  + $ ./demo-full.sh -h

  + ./demo-full.sh: run all 'demo.sh' scripts using libdemo

  + -l|--lint: run linter on shell files

  + -a|--auto: run in automatic mode

  + -h|--help|-?: Show usage

  + ```

  +

  + Available environment variables:

  +

  + * `LIBDEMO_USE_COLOUR`: enable (1, default) or disable (0) the use of colour in libdemo. Colours may still appear in output from other packages.

  + * `LIBDEMO_USE_UNICODE`: enable (1, default) or disable (0) the use of unicode in libdemo. Unicode may still appear in output from other packages.

  + * `LIBDEMO_INTERACTIVE`: enable (1, default) or disable (0) interactive mode. In non-interactive (automatic) mode, there is no waiting for input and some commands (prefixed with `i`) are skipped.

  +

  + ## libdemo

  +

  + An attempt at making live, but prepared, presentations in bash.

  +

  + Demo files `demo.sh` are bash files that source `libdemo.sh`, providing some convenience functions and abbreviated forms for them:

  +

  + * `h` Print arguments as a header.

  + * `,` Print arguments as regular text.

  + * `x` Execute arguments, expect success.

  + * `f` Execute arguments, expect failure.

  + * `i` Execute arguments in interactive mode only. Ignore exit status.

  + * `c` Clear terminal.

  +

  + Additional functions are provided that can be used in commands:

  +

  + * `pygmentize`: Wrapper around [pygmentize](https://pygments.org/docs/cmdline/).