backtick auto-discovery key usage advice

Author: dwijnand

src/cargo/util/toml/targets.rs

@@ -603,7 +603,7 @@ files will be included as a {target_kind_human} target:
 {rem_targets_str}
 This is likely to break cargo build or cargo test as these files may not be
 ready to be compiled as a {target_kind_human} target today. You can future-proof yourself
-and disable this warning by adding {autodiscover_flag_name} = false to your [package]
+and disable this warning by adding `{autodiscover_flag_name} = false` to your [package]
 section. You may also move the files to a location where Cargo would not
 automatically infer them to be a target, such as in subfolders.
 

tests/testsuite/bench.rs

@@ -762,7 +762,7 @@ files will be included as a benchmark target:
 
 This is likely to break cargo build or cargo test as these files may not be
 ready to be compiled as a benchmark target today. You can future-proof yourself
-and disable this warning by adding autobenches = false to your [package]
+and disable this warning by adding `autobenches = false` to your [package]
 section. You may also move the files to a location where Cargo would not
 automatically infer them to be a target, such as in subfolders.
 

tests/testsuite/run.rs

@@ -455,7 +455,7 @@ files will be included as a example target:
 
 This is likely to break cargo build or cargo test as these files may not be
 ready to be compiled as a example target today. You can future-proof yourself
-and disable this warning by adding autoexamples = false to your [package]
+and disable this warning by adding `autoexamples = false` to your [package]
 section. You may also move the files to a location where Cargo would not
 automatically infer them to be a target, such as in subfolders.