docs: add README.md and update form submission logic (#21)

This commit updates the README.md with project details, including features, technologies, installation instructions, and project structure.
- It also includes a description of the app, features like free-text input, sentiment selection, submitting content to a server, and displaying a Snackbar.
- It updates the form submission logic in `App.kt` to delay showing the "Feedback sent" Snackbar by 1 second.

Closes #2

Reviewed-on: #21
Co-authored-by: Ben Martin <ben.martin@sky.uk>
Co-committed-by: Ben Martin <ben.martin@sky.uk>

composeApp/src/commonMain/kotlin/uk/sky/bob/application/App.kt

@@ -31,6 +31,7 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.text.input.TextFieldValue
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
+import kotlinx.coroutines.delay
 import kotlinx.coroutines.launch
 import org.jetbrains.compose.ui.tooling.preview.Preview
 
@@ -85,7 +86,10 @@ fun App() {
                         Button(onClick = {
                             sentiment.value = Sentiment.HAPPY
                             comment = TextFieldValue("")
-                            scope.launch { scaffoldState.snackbarHostState.showSnackbar("Feedback sent") }
+                            scope.launch {
+                                delay(1000)
+                                scaffoldState.snackbarHostState.showSnackbar("Feedback sent")
+                            }
                         }, modifier = Modifier.padding(8.dp)) {
                             Icon(Icons.AutoMirrored.Filled.Send, contentDescription = "Send")
                         }