message: Change example in README to reflect tilde expansion rules
diff: @@ -207,7 +207,7 @@ The `export` command works similarly to the `let` command, but instead of defini
  global variable that other processes can access.
  ```ion
  -export PATH = "~/.cargo/bin:${PATH}"
  +export PATH = ~/.cargo/bin:${PATH}
  ```
  ### Export Arithmetic
  