Apply suggestions from code review

Co-authored-by: antoyo <antoyo@users.noreply.github.com>

Author: FrancescoV1985

CONTRIBUTING.md

@@ -25,8 +25,6 @@ We encourage new contributors to join our communication channels and introduce t
 
 ## Understanding Core Concepts
 
-
-
 ### Sysroot & compilation flags
 
 #### What *is* the sysroot?

build_system/src/build.rs

@@ -45,15 +45,15 @@ impl BuildArg {
         println!(
             r#"
 `build` command help:
-    --release              : Build backend in release mode with optimized dependencies without rebuilding sysroot
+    --release              : Build backend in release mode with optimized dependencies
     --sysroot              : When used on its own, build backend in dev. mode with optimized dependencies
                              and sysroot in dev. mode (unoptimized)
                              When used together with --release, build backend in release mode with optimized dependencies
                              When used together with --release-sysroot,
                              build the sysroot in release mode with optimized dependencies instead of in dev. mode
     --release-sysroot      : When combined with --sysroot, additionally
                              build the sysroot in release mode with optimized dependencies.
-                             When combined with --release, it has no effect.
+                             It has no effect if `--sysroot` is not specified.
                              It should not be used on its own."#
         );
         ConfigInfo::show_usage();