figlet: add page (#1247)

pages/linux/figlet.md

@@ -0,0 +1,15 @@
+# figlet
+
+> Generate ASCII banners from user input.
+
+- Generate by directly inputting text:
+
+`figlet {{input_text}}`
+
+- Use a custom font file:
+
+`figlet {{input_text}} -f {{font_file_name}}`
+
+- Pipe command output through figlet:
+
+`{{command}} | figlet`