add info about vim-pio

[normen]

Shameless plug of my plug 🙂

As the linked vim plugin doesn't seem to be maintained I added information about my own vim plugin for PlatformIO to the vim integration page.

I hope this PR is formally correct.

[CLAassistant]

All committers have signed the CLA.

[ivankravets]

Thank you so much for the great plugin and your contribution! 🙏

How does work autocompletion in the VIM? How did you setup it? Does it make sense to update our docs for VIM? We have not updated it since 2016 :(

[normen]

Hey, I added some info in my plugins README.md on how to enable completion using the coc-nvim or vim-lsp plugins. Installing a LSP plugin in VIM is relatively involved but as soon as ccls is up and running its quite smooth sailing.

The PlatformIO-generated .ccls file works fine, though ccls is slowly getting replaced by clangd in many projects so optionally having a compile-commands.json would be in order at some point? Maybe clangd can even use .ccls files, I didn't dig into that. At any instance, it works as intended.

Thank you for this great ecosystem around microcontrollers, it really pushed the Arduino scene forward!