Load prompts from external url also rather than only inbuilt slash commands

[digitalneedstech]

Validations

• [ ] I believe this is a way to improve. I'll try to join the Continue Discord for questions
• [ ] I'm not able to find an open issue that requests the same enhancement

Problem

Some customers doesnt want to show their prompts being used in house to end users to avoid multiple reasons like prompt injection attacks for example.

Solution

We should have a feature in Continue plugin that loads prompts from external URLs also rather than a file by the name of *.prompt or written in config.json