Move pages under tldr, lint run.sh, update docs

tldr/mkdir

@@ -0,0 +1,21 @@
+---
+syntax: markdown
+tags: [tldr, common]
+source: https://github.com/tldr-pages/tldr.git
+---
+# mkdir
+
+> Create directories and set their permissions.
+> More information: <https://www.gnu.org/software/coreutils/mkdir>.
+
+- Create specific directories:
+
+`mkdir {{path/to/directory1 path/to/directory2 ...}}`
+
+- Create specific directories and their [p]arents if needed:
+
+`mkdir -p {{path/to/directory1 path/to/directory2 ...}}`
+
+- Create directories with specific permissions:
+
+`mkdir -m {{rwxrw-r--}} {{path/to/directory1 path/to/directory2 ...}}`