v1: Add CTX_SIZE for CodeLlama max context size (#16)

* Add CTX_SIZE as an optional parameter with a default value of '64000' and use it in the main.py file.

* Change delay time from 2 seconds to 30 seconds in query_llama function.

* Remove URL from error message to maintain URL secret

* Update 'n_keep' value in dictionary to be an integer instead of a string.