Docs: fix old codecov URL based on CRAN comments

README.md

@@ -12,7 +12,7 @@
     <a align="center" href="https://github.com/mihaiconstantin/powerly/actions"><img src="https://github.com/mihaiconstantin/powerly/workflows/R-CMD-check/badge.svg" alt="R-CMD-check" /></a>
     <a href="https://www.r-pkg.org/pkg/powerly"><img src="https://www.r-pkg.org/badges/version/powerly" alt="CRAN version"/></a>
     <a href="https://cranchecks.info/pkgs/powerly"><img src="https://cranchecks.info/badges/worst/powerly" alt="CRAN checks"/></a>
-    <a href="https://codecov.io/gh/mihaiconstantin/powerly"><img src="https://codecov.io/gh/mihaiconstantin/powerly/branch/main/graph/badge.svg?token=YUCO8ULBCM" alt="Code coverage"/></a>
+    <a href="https://app.codecov.io/gh/mihaiconstantin/powerly"><img src="https://codecov.io/gh/mihaiconstantin/powerly/branch/main/graph/badge.svg?token=YUCO8ULBCM" alt="Code coverage"/></a>
     <a href="https://www.repostatus.org/#active"><img src="https://www.repostatus.org/badges/latest/active.svg" alt="Repository status"/></a>
     <a href="https://www.r-pkg.org/pkg/powerly"><img src="https://cranlogs.r-pkg.org/badges/grand-total/powerly" alt="CRAN RStudio mirror downloads"/></a>
 </p>