Update INSTALL.md

Author: swaroopch

INSTALL.md

@@ -1,6 +1,18 @@
 ```
-npm install -g gitbook-cli
-gitbook serve
+# install honkit
+npm install honkit --save-dev
+
+# show website running locally
+npx honkit serve
+
+# generate website files
+npx honkit build . public --log=debug
+
+# generate pdf
+npx honkit pdf . byte-of-python.pdf
+
+# generate epub
+npx honkit epub . byte-of-python.epub
 ```
 
-See http://toolchain.gitbook.com/ebook.html
+See https://github.com/honkit/honkit and https://honkit.netlify.app/