chore: add README, go.mod, and go.sum for Term Tier project

- Created README.md with project description, features, installation instructions, usage, key bindings, project structure, and license information.
- Initialized go.mod to manage dependencies for the Term Tier application.
- Generated go.sum to ensure consistent dependency resolution.

.gitignore

@@ -0,0 +1,15 @@
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+*.test
+*.out
+go.work
+.vscode/
+.idea/
+# Goreleaser
+dist/
+.DS_Store
+Thumbs.db
+/termtier