commit backtick suggestion

Co-authored-by: Robert Pająk <[email protected]>

specification/context/api-propagators.md

@@ -238,7 +238,7 @@ For many language implementations, the GetAll function will be added after the s
 For these languages, requiring implementations of Getter to include GetAll constitutes a breaking change
 since instrumentation which previously functioned would fail. Language implementations should be cognizant
 of this, and add GetAll in a way that retains backwards compatibility. For example, by providing a default
-GetAll implementation based on Get, or by creating an extended Getter type.
+`GetAll` implementation based on Get, or by creating an extended `Getter` type.
 
 If explicitly implemented, the `GetAll` function MUST return all values of the given propagation key.
 It SHOULD return them in the same order as they appear in the carrier.