feat(library): Updated the README for base

Signed-off-by: Ujjwal Mahar <ujjwal.mahar01@gmail.com>

Author: UjjwalMahar

library/base/README.md

@@ -0,0 +1,11 @@
+# Base Image
+
+Base image is a Unikraft runtime built from [app-elfloader]() that loads and runs Linux native binaries using the [binary-compatibility mode](https://unikraft.org/docs/concepts/compatibility).
+
+This directory contains the definition for the `unikraft.org/base:latest` image.
+
+To run this image, [install Unikraft's companion command-line tool chain `kraft`](https://unikraft.org/docs/cli) and then you can run:
+
+```
+kraft run unikraft.org/base:latest
+```