Adopt streamlit's auto submit feature via ctrl+enter

[Xuanwo]

chatgpt-toolbox/main.py

Lines 31 to 32 in ee36426

	if st.button('Improve my writing'):
	if text == "":

Hello! Streamlit provides built-in support for using Ctrl+Enter to submit content. Perhaps we can modify the check here to allow it to work?

reference: https://docs.streamlit.io/library/api-reference/widgets/st.text_input

[Xuanwo]