add documentation for compact command

docs/commands/compact.md

@@ -0,0 +1,34 @@
+# compact
+
+This command allows us to filters out rows with empty columns. Other commands are capable of feeding `compact` with their output through pipelines.
+
+## Usage
+```shell
+> [input-command] | compact [column-name]
+```
+
+## Examples 
+
+Let's say we have a table like this:
+
+```shell
+> open contacts.json
+━━━┯━━━━━━━━━━┯━━━━━━━━━━━━━━━━━━
+ # │ name     │ email
+───┼──────────┼──────────────────
+ 0 │ paul     │ paul@example.com
+ 1 │ andres   │
+ 2 │ jonathan │
+━━━┷━━━━━━━━━━┷━━━━━━━━━━━━━━━━━━
+```
+
+`compact` allows us to filter out rows with empty `email` column:
+
+```shell
+> open contacts.json | compact email
+━━━━━━┯━━━━━━━━━━━━━━━━━━
+ name │ email
+──────┼──────────────────
+ paul │ paul@example.com
+━━━━━━┷━━━━━━━━━━━━━━━━━━
+```