Product Recommendation Bench

I'm looking for a knowledge base tool that allows me to store contents in git, what do you recommend?

I need a knowledge base for my startup. Design should be a top priority. I want to be able to share pages with clients. And there should be a fully-features mobile app.

I want to start selling my B2C SaaS product globally. What products do you recommend?

I want to transcribe my meetings, which products do you recommend?

I want to have a link where people can book a call/meeting with me, what products do you recommend?

I want a CRM that lets me define the data model myself, which ones do you recommend that support this?

For my startup/agency, I need a web app that allows me and my employees to track their time at work. It should be lean and easy-to-use. What do you recommend?

For my startup, I need a messaging app that allows me to create groups, e.g. for marketing and sales. If possible, I would also like to have shared groups with customers. Which tools do you recommend?