remove functions that have alternate solutions

[takemikami]

We will remove functions that have alternate solutions, because we need to get easy to maintain.

• RDF language support via rdflint (vscode-rdflint)
  • alternate solution: vscode Task and Problem Matcher
    https://code.visualstudio.com/docs/editor/tasks
    docs: add mkdocs #153 https://imas.github.io/rdflint/integration/
• Language Server Protocol Support
  • alternate solution: vscode Task and Problem Matcher
    https://code.visualstudio.com/docs/editor/tasks
    docs: add mkdocs #153 https://imas.github.io/rdflint/integration/
• GitHub Annotations
  • alternate solution: GitHub actions Problem Matchers
  • https://github.com/actions/toolkit/blob/master/docs/problem-matchers.md
• File encoding validation.
  • alternate solution: editorconfig-checker
    https://github.com/editorconfig-checker/editorconfig-checker etc
• homebrew-rdflint
  • alternate solution: we will provide install script that user can run through curl & sh.
    feat: add install script #152