Fix issues with new chafa

[Frederick888]

92b284a fix: add chafa arguments '--format symbols'

Otherwise chafa chooses a protocol based on the terminal.

46a42fb fix: use chafa arguments '--polite on' to suppress escape sequences

Chafa printed '\033[?25h' to hide the cursor.

Adding a table.remove(data, 1) works too under *nix but '--polite on'
should cater for Windows at the same time.

[1] https://github.com/hpjansson/chafa/blob/aa8a3d928c9b476f548c9c79cce03cc80f437239/tools/chafa/chafa.c#L1656-L1659

3c8f412 fix: migrate to new vim.health APIs

Fixes #8

Fixes #10