docs: add missing flag in README

Author: Simon Renoult

README.md

@@ -40,6 +40,7 @@ $ npx code-complexity <path-to-git-directory or URL> [options]
       -i, --since [since]                   limit analysis to commits more recent in age than date
       -u, --until [until]                   limit analysis to commits older in age than date
       -s, --sort [sort]                     sort results (allowed valued: score, churn, complexity or file)
+      -d, --directories                     display values for directories instead of files
       -h, --help                            display help for command
 
     Examples:

src/io/cli.ts

@@ -77,7 +77,7 @@ function getRawCli(
     )
     .option(
       "-d, --directories",
-      "Display values for directories instead of files"
+      "display values for directories instead of files"
     )
     .on("--help", () => {
       console.log();