Reword 'Setup' a bit

Author: phansch

README.md

@@ -107,13 +107,13 @@ script:
   - cargo clippy
   # if you want the build job to fail when encountering warnings, use
   - cargo clippy -- -D warnings
-  # in order to also check tests and none-default crate features, use
+  # in order to also check tests and non-default crate features, use
   - cargo clippy --all-targets --all-features -- -D warnings
   - cargo test
   # etc.
 ```
 
-It might happen that Clippy is not available for a certain nightly release.
+If you are on nightly, It might happen that Clippy is not available for a certain nightly release.
 In this case you can try to conditionally install Clippy from the git repo.
 
 ```yaml

doc/adding_lints.md

@@ -23,9 +23,10 @@ because that's clearly a non-descriptive name.
 
 ### Setup
 
-Clippy depends on the current git master version of rustc, which can change rapidly. Make sure you're
-working near rust-clippy's master, and use the `setup-toolchain.sh` script to configure the appropriate
-toolchain for this directory.
+When working on Clippy, you will need the current git master version of rustc,
+which can change rapidly. Make sure you're working near rust-clippy's master,
+and use the `setup-toolchain.sh` script to configure the appropriate toolchain
+for the Clippy directory.
 
 ### Testing