create a home for cool one liners

I was inspired to create this directory from conversation in #general.

I feel like capturing any and all unstructured one-liners would be a
wonderful resource for learning nu.

It could open doors for automation. For example, we mirror contributions
to `cool_oneliners` to the discord channel.

cool_oneliners/README.md

@@ -0,0 +1,19 @@
+# cool oneliners
+
+Capturing oneliners to and from the nushell Discourse channel `#cool-oneliners`.
+
+Consider these a living library.
+Or an ongoing story of how people actually use `nu`.
+
+## Naming and script requirements
+
+- the filename should be an abbreviation of the general topic of the script
+  For example:
+
+  ```sh
+  git_batch_extract.nu
+  ```
+
+- the script should have two lines
+  - the first line should be a comment describing the script's purpose
+  - the second line should be the cool oneliner