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

tldr/bg

@@ -0,0 +1,17 @@
+---
+syntax: markdown
+tags: [tldr, common]
+source: https://github.com/tldr-pages/tldr.git
+---
+# bg
+
+> Resume suspended jobs (e.g. using `Ctrl + Z`), and keeps them running in the background.
+> More information: <https://manned.org/bg>.
+
+- Resume the most recently suspended job and run it in the background:
+
+`bg`
+
+- Resume a specific job (use `jobs -l` to get its ID) and run it in the background:
+
+`bg %{{job_id}}`