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

tldr/cmark

@@ -0,0 +1,25 @@
+---
+syntax: markdown
+tags: [tldr, common]
+source: https://github.com/tldr-pages/tldr.git
+---
+# cmark
+
+> Converts CommonMark Markdown formatted text to other formats.
+> More information: <https://github.com/commonmark/cmark>.
+
+- Render a CommonMark Markdown file to HTML:
+
+`cmark --to html {{filename.md}}`
+
+- Convert data from `stdin` to LaTeX:
+
+`cmark --to latex`
+
+- Convert straight quotes to smart quotes:
+
+`cmark --smart --to html {{filename.md}}`
+
+- Validate UTF-8 characters:
+
+`cmark --validate-utf8 {{filename.md}}`