Add, remove, and fix links, descriptions, and spelling

[Raymond-Adams]

Closes #59

Summary: updated links, descriptions, and some spelling inconsistencies.

Removed

• Degreed: a learning ecosystem for businesses
• Vertabelo Academy: non-essential, see DataCamp instead
• learnlayout.com: non-essential/redundant
• Crate Code: non-essential/redundant
• itunes.stanford.edu: redirects to a list of non-programming-related podcasts
• github.com/1millionwomentotech/toolkitten: non-essential/redundant
• Paqmind: no longer maintained and does not own paqmind.com, see: https://github.com/Paqmind/platform
• Metacademy: redundant, see roadmap.sh

Added

• The Odin Project: free full-stack curriculum and an open-source community.
• Level Up Tutorials: large library of high-quality web videos from the co-host of Syntax.fm
• DataCamp: one of, if not the best interactive platforms for learning data science
• Roadmap.sh: developer roadmaps for various career and skill paths.

[karlhorky]

• learnlayout.com: non-essential/redundant

not sure why this change was made, but I'll revert it

[karlhorky]

Thanks!

[UnrestrictedAccess]

How do I fix links for iPhone using this code