Correct regular expression for readme filename

Author: per1234

check/checkfunctions/checkfunctions.go

@@ -70,7 +70,7 @@ func containsIncorrectPathBaseCase(pathList paths.PathList, correctBaseName stri
 // MissingReadme checks if the project has a readme that will be recognized by GitHub.
 func MissingReadme() (result checkresult.Type, output string) {
 	// https://github.com/github/markup/blob/master/README.md
-	readmeRegexp := regexp.MustCompile(`(?i)^readme\.(markdown)|(mdown)|(mkdn)|(md)|(textile)|(rdoc)|(org)|(creole)|(mediawiki)|(wiki)|(rst)|(asciidoc)|(adoc)|(asc)|(pod)|(txt)`)
+	readmeRegexp := regexp.MustCompile(`(?i)^readme\.(markdown)|(mdown)|(mkdn)|(md)|(textile)|(rdoc)|(org)|(creole)|(mediawiki)|(wiki)|(rst)|(asciidoc)|(adoc)|(asc)|(pod)|(txt)$`)
 
 	// https://docs.github.com/en/free-pro-team@latest/github/creating-cloning-and-archiving-repositories/about-readmes#about-readmes
 	if pathContainsReadme(checkdata.ProjectPath(), readmeRegexp) ||