Fix broken links and update documentation

[sb2nov]

Changes

• Fixed broken Docusaurus link (removed double slash)
• Updated 1Password link from agilebits.com to 1password.com
• Updated documentation URLs for GitHub (help.github.com → docs.github.com)
• Updated Go website links (golang.org → go.dev)
• Updated Octave link (gnu.org → octave.org)
• Updated Doom Emacs repository and installation instructions
• Updated SSH key generation to use ed25519 instead of rsa
• Updated bash-completion installation to use bash-completion@2
• Modernized Go, Docker, Python, and Java documentation
• Reorganized apps list with new categories (AI Tools, Communication)
• Added new tools: Raycast, Warp, Cursor, Zed, GitHub Desktop, Shottr
• Updated Homebrew installation instructions for Apple Silicon support
• Improved PostgreSQL and Java installation documentation
• Removed obsolete apps and deprecated instructions
• Updated various Homebrew paths for cross-platform compatibility