Correcting accidental escape characters

[cjglo]

It seems that some escape characters were copied in the README and the highlighted MarkDown isn't showing its messing with the strings.

First example when run currently:

$ cargo run
   Compiling tracker v0.1.0 (/mydirectory)
error: unknown start of token: \
 --> src/main.rs:9:68
  |
9 |     let response = tokio_test::block_on(provider.get_latest_quotes(\"AAPL\", \"1d\")).unwrap();
  |                                                                    ^

error[E0765]: unterminated double quote string
  --> src/main.rs:9:69
   |
9  |       let response = tokio_test::block_on(provider.get_latest_quotes(\"AAPL\", \"1d\")).unwrap();
   |  _____________________________________________________________________^
10 | |     // extract just the latest valid quote summery
11 | |     // including timestamp,open,close,high,low,volume
12 | |     let quote = response.last_quote().unwrap();
...  |
15 | |     println!(\"At {} quote price of Apple was {}\", time, quote.close);
16 | | }
   | |_^

Edited version:

$ cargo run
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.13s
     Running `target/debug/tracker`
At 2024-09-10 13:30:00.0 +00:00:00 quote price of Apple was 220.11000061035156