feat: enhance README with detailed usage examples and output for BDD testing

Author: dlidstrom

Readme.md

@@ -1,3 +1,120 @@
 # Sprout: BDD Testing for F#
 
-![logo](sprout.png)
+<img src="logo.png" height="128" width="128" />
+
+## Usage
+
+```fsharp
+open Sprout
+
+let s1 = describe "Suite 1" {}
+let s2 = describe "Suite 2" {
+  beforeEach {
+    debug "Before each test in Suite 2"
+  }
+
+  it "should pass in Suite 2" {
+    info "This test passes in Suite 2"
+  }
+}
+
+// run collection of suites
+runTestSuite (describe "Main Suite" { s1; s2 })
+
+// larger suite example
+let suite = describe "A larger test suite" {
+  beforeEach {
+    debug "Before each test"
+  }
+
+  afterEach {
+    debug "After each test"
+  }
+
+  it "should pass" {
+    info "This test passes"
+  }
+
+  it "should fail" {
+    info "This test fails"
+    failwith "Intentional failure"
+  }
+
+  pending "This is a pending test"
+
+  describe "Nested suite" {
+    it "should also pass" {
+      info "Nested test passes"
+    }
+  }
+
+  describe "Arithmetic" {
+    describe "Addition" {
+      it "should add two numbers correctly" {
+        let result = 2 + 2
+        result |> shouldEqual 4
+      }
+
+      it "should handle negative numbers" {
+        let result = -1 + -1
+        result |> shouldEqual -2
+      }
+    }
+
+    describe "Faulty Addition" {
+      it "should fail when adding incorrect numbers" {
+        let result = 2 + 2
+        result |> shouldEqual 5
+      }
+    }
+  }
+}
+
+runTestSuite suite
+```
+
+Output:
+
+```txt
+Main Suite
+  Suite 1
+  Suite 2
+  Before each test in Suite 2
+  This test passes in Suite 2
+    ✅ passed: should pass in Suite 2
+All tests passed!
+Summary: 1 passed, 0 failed, 0 pending
+A larger test suite
+Before each test
+This test passes
+After each test
+  ✅ passed: should pass
+Before each test
+This test fails
+After each test
+  ❌ failed: should fail - Intentional failure
+Before each test
+After each test
+  ❔ pending: This is a pending test
+  Nested suite
+  Before each test
+  Nested test passes
+  After each test
+    ✅ passed: should also pass
+  Arithmetic
+    Addition
+    Before each test
+    After each test
+      ✅ passed: should add two numbers correctly
+    Before each test
+    After each test
+      ✅ passed: should handle negative numbers
+    Faulty Addition
+    Before each test
+    After each test
+      ❌ failed: should fail when adding incorrect numbers - Expected 5 but got 4
+There were 2 test failures:
+- A larger test suite / should fail - Intentional failure
+- A larger test suite / Arithmetic / Faulty Addition / should fail when adding incorrect numbers - Expected 5 but got 4
+Summary: 4 passed, 2 failed, 1 pending
+```