Ch. 17: rewrite 17.01 with a better example

Add `reqwest` and `scraper` dependencies to the `trpl` crate. Wrap them
in `trpl` re-exports which keep the API surface low.

Rewrite the whole first section to use `race` along with those `trpl`
re-exports to show a more “real” example of async code right form the
start, including actual concurrency, unlike the previous introduction.

Update 17.03 to account for having introduced `race` already, and update
listing numbers for rewritten 17.01.

Cargo.toml

@@ -1,5 +1,5 @@
 [workspace]
-members = ["packages/tools"]
+members = [ "listings/ch17-async-await/listing-scraper-01","packages/tools"]
 default-members = ["packages/tools"]
 resolver = "2"
 exclude = [