Remove non-contextual section in "Develop Lints with Tests" + typo

Author: blyxyas

book/src/development/writing_tests.md

@@ -3,10 +3,7 @@
 Developing lints for Clippy is a Test-Driven Development (TDD) process because
 our first task before implementing any logic for a new lint is to write some test cases.
 
-## Develop Lint with Tests
-
-It is not necessarily that every Clippy developer enjoys having the compiler screaming
-test failures in their face. Some embrace TDD *while* others learn to peacefully co-exist with it.
+## Develop Lints with Tests
 
 When we develop Clippy, we enter a complex and chaotic realm full of 
 programmatic issues, stylistic errors, illogical code and non-adherence to convention.