Added examples.

examples/playground/Cargo.toml

@@ -0,0 +1,20 @@
+[package]
+name = "playground"
+description = """The playground example is a special example meant for unstructured experimentation which can potentially be turned
+into an actual example at some point or deleted. It should always be reset to unchanged hello world before the working
+branch where the experimentation is happening is merged."""
+version.workspace = true
+edition.workspace = true
+repository.workspace = true
+readme.workspace = true
+license.workspace = true
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+thiserror.workspace = true
+uom.workspace = true
+log.workspace = true
+env_logger.workspace = true
+futures-lite.workspace = true
+async-io.workspace = true