Shell-gpt

* Native `$SHELL` command execution instead of default `/bin/sh`.
* Better integration with Powershell and CMD on Windows.
* Fixed a bug with pyreadline3 dependency for Windows systems.
* Fixed a bug when sgpt couldn't recognize Powershell or CMD on Windows.

New awesome REPL mode for chat sessions. To start a chat session in REPL mode, use the `--repl` option followed by a unique session name. You can also use "temp" as a session name to start a temporary REPL session. Note that `--chat` and `--repl` are using same chat sessions, so you can use `--chat` to start a chat session and then use `--repl` to continue the conversation in REPL mode. REPL mode will also show history of your conversation in the beginning. REPL mode can work with `--shell` and `--code` options, which makes it very handy for interactive shell commands and code generation.

<p align="center">
<img src="https://s10.gifyu.com/images/repl-demo.gif" alt="gif">
</p>

* Changed default temperature value to 0.1 (more accurate responses).
* Optimisation, command line option validations.
* Refactoring code base.

* Fixing bug with `--show-chat` (was crashing), fixing issue with prompts in `--chat` mode.
* Added validation error for initiated `--chat`. Options `--code` and `--shell` now can't be passed to initiated chat, which was initated with oposite option, e.g. if `--chat` was created with `--shell`, we can't follow the session with `--code`.

* Streaming response from OpenAI API by parsapoorsh
* `--execute` option was removed, `--shell` will be prompting for execute by default.
* No more request preloads, loading spinner was removed.
* Prompt engineering: accurate suggestions for `--shell` and `--code`.

* Runtime configuration file `~/.config/shell_gpt/.sgptrc`
* Possibilty to setup some parameters in `.sgptrc`
* Project structure and code improvements