Content for submodules [WIP]

[thessaly]

Hi,

I'm opening this PR that I will be updating as I keep working on the content.

• [x] OHM basics
• [x] 1. Welcome to OHM
• [ ] 2. Staging your project
• [ ] 3. Building your project
• [ ] 4. OH specifics
• [ ] 5. Roadmapping
• [ ] 6. Licenses and standards
• [ ] 7. Community and communication
• [ ] 8. OHM Outro