remove backticks from titles

This doesn't actually display correctly

src/doc/trpl/SUMMARY.md

@@ -7,22 +7,22 @@
 * [Learn Rust](learn-rust.md)
 * [Effective Rust](effective-rust.md)
     * [The Stack and the Heap](the-stack-and-the-heap.md)
-    * [`Debug` and `Display`](debug-and-display.md)
+    * [Debug and Display](debug-and-display.md)
     * [Testing](testing.md)
     * [Documentation](documentation.md)
     * [Iterators](iterators.md)
     * [Concurrency](concurrency.md)
     * [Error Handling](error-handling.md)
     * [FFI](ffi.md)
-    * [`Deref` coercions](deref-coercions.md)
+    * [Deref coercions](deref-coercions.md)
 * [Syntax and Semantics](syntax-and-semantics.md)
     * [Variable Bindings](variable-bindings.md)
     * [Primitive Types](primitive-types.md)
     * [Functions](functions.md)
     * [Comments](comments.md)
-    * [`if`](if.md)
-    * [`for` loops](for-loops.md)
-    * [`while` loops](while-loops.md)
+    * [if](if.md)
+    * [for loops](for-loops.md)
+    * [while loops](while-loops.md)
     * [Ownership](ownership.md)
     * [References and Borrowing](references-and-borrowing.md)
     * [Lifetimes](lifetimes.md)

src/doc/trpl/debug-and-display.md

@@ -1,3 +1,3 @@
-% `Debug` and `Display`
+% Debug and Display
 
 Coming soon!

src/doc/trpl/for-loops.md

@@ -1,4 +1,4 @@
-% `for` Loops
+% for Loops
 
 The `for` loop is used to loop a particular number of times. Rust's `for` loops
 work a bit differently than in other systems languages, however. Rust's `for`

src/doc/trpl/if.md

@@ -1,4 +1,4 @@
-% `if`
+% if
 
 Rust's take on `if` is not particularly complex, but it's much more like the
 `if` you'll find in a dynamically typed language than in a more traditional

src/doc/trpl/while-loops.md

@@ -1,4 +1,4 @@
-% `while` loops
+% while loops
 
 The other kind of looping construct in Rust is the `while` loop. It looks like
 this: