Revised contributing.md, edited docs (#1951)

* Added Overview page

* Revised Getting Started page

* Minor revision

* Edited readme, minor modifications to docs

* Removed sweep.yaml, .devcontainer, .ergomake

* Moved security.md to .github, added contributing.md

* changes as per code review

* updated contributing.md

* fixed broken links & added missing links in doc, improved structure

* fixed link in wsl setup

* fixed server link, added https cloning in yarn-setup

.gitignore

@@ -2,4 +2,4 @@
 .DS_Store
 node_modules/
 # yarn is the recommended package manager across the project
-.package-lock.json
+.package-lock.json