[feat] allow users an option to specify a prompt if they want to

[AmanNegi]

Description

We currently support /gen-gif {your-query-here} which is great and generates a few prompt on the basis of your query. However, we should also allow users to enter their prompt if they don't wish or are not able to generate the desired prompt.

Implementation

Any user should be able to enter their own prompt using the p or prompt flag in the command.

/gen-gif p "your-prompt-here"
/gen-gif prompt "your-prompt-here"