[feature] Add a function to send keypress to the terminal

[blurskye]

we need a way to send keypress to terminal..... some users might want to send ctrl+c(keyboard interupt) to the terminal, specifically with code-runners that use toggle-term to run code.... to stop execution

https://github.com/akinsho/toggleterm.nvim/assets/145671529/7fe03dfa-4f41-4677-8880-7c7b74013337 video might a little out of point here, but the code-runners can infact benifit greatly from such a feature

there might be hacky ways to send ctrl+c, but those arent bullet proof method, so i am requesting a Feed keypress to terminal here

thanks in advance