Adding features doc. (#219)

* Adding features doc.

* Cleaned up doc.

docs/features.md

@@ -0,0 +1,30 @@
+# Cover Agent Feature Flags
+
+## Features Overview
+
+### 1. Diff-Based Coverage
+Generates targeted tests for changes between branches, helping ensure new code is adequately tested without re-running all tests.
+
+- **Options**:
+  - `--diff-coverage`: Enables diff-based test generation.
+  - `--branch=<branch_name>`: Specifies a branch for comparison (default: `main`).
+- **Usage**:
+  ```bash
+  python cover_agent/main.py --diff-coverage --branch=develop
+  ```
+  This example compares the current branch with `develop`, generating tests for new changes.
+
+- **Note**: `--diff-coverage` cannot be used with `--use-report-coverage-feature-flag`.
+
+### 2. Report-Based Coverage
+Accepts tests if they increase coverage for any file in the report, regardless of the specific source file.
+
+- **Option**:
+  - `--use-report-coverage-feature-flag`: Activates this feature to accept any coverage increase as sufficient.
+- **Usage**:
+  ```bash
+  python cover_agent/main.py --use-report-coverage-feature-flag
+  ```
+  This example accepts tests that improve coverage anywhere in the report.
+
+- **Note**: This flag is mutually exclusive with `--diff-coverage`.