Improve sandbox documentation

[amotl]

One more point - it would be good to have for external contributors a page, which will describe how to setup a development environment locally (otherwise one is forced to run tests/check results mostly via git commits)

Originally posted by @serhiy-yevtushenko in #237

[amotl]

Hi @serhiy-yevtushenko. May we ask you to review the development sandbox document [1], and tell us which details you would like to see being improved? Please also submit patches to enhance it at your disposal.

[1] https://github.com/grafana-toolbox/grafana-client/blob/main/docs/development.md

[serhiy-yevtushenko]

I believe the main issues for me was at all to find this document.

It's referred at the bottom in the README.md (and so, one would not be able to find it, without scrolling through the whole readme.md), and as well, when one checks out the project, I was not able to find it easily, because it is located in docs folders, so, I was not able to see it. For me the main complications were as well usage of not very known tool set (I worked before with conda, poetry and uv, but project is not using any of them). Other problem was, that when I was trying to run script for generating async version of API, using poe (on windows), I was getting errors.

Now, when I try to follow the instruction, the first issue that I occur on Windows 11 platform, I get the following issue on the second step:
python3 -m venv .venv
'python3' is not recognized as an internal or external command,
operable program or batch file.

[serhiy-yevtushenko]

On windows one should use

py  -m venv .venv
.\.venv\Scripts\activate.bat

[serhiy-yevtushenko]

And even when I use it, I get the following exception on poe format:

File "C:\Program Files\WindowsApps\PythonSoftwareFoundation.Python.3.13_3.13.2032.0_x64__qbz5n2kfra8p0\Lib\subprocess.py", line 1554, in _execute_child
    hp, ht, pid, tid = _winapi.CreateProcess(executable, args,
                       ~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^
                             # no special security
                             ^^^^^^^^^^^^^^^^^^^^^
    ...<4 lines>...
                             cwd,
                             ^^^^
                             startupinfo)
                             ^^^^^^^^^^^^
OSError: [WinError 193] %1 is not a valid Win32 application

which comes from call in poe:

    sys.exit(main())

[amotl]

Hi again. Thank you very much for the detailed reports about the flaws you have observed when approaching the project from a developer's perspective, specifically when using Windows. We will try to address them properly, and will also be happy to receive any relevant patches.