QOL: Add config option to start in insert mode for empty files

[jerhos]

When opening a new file, I frequently find myself trying to write, only to find I am still in normal mode - often having written a mess of characters in the process.

I propose an option in the configuration file to start in insert mode when opening empty files (and by extension, when creating new files). There is no need to navigate an empty file and therefore no apparent advantage to start in normal mode. I can think of only two reasons to keep it as it is:

1. Consistency across all files (for people who can remember to press i)
2. Instant access to commands (but most of those aren't useful in the context of an empty file anyway)

No. 1 is why I would like to see this as an option that needs to be actively toggled on.
I would appreciate hearing other opinions and suggestions on this.