updated README build instructions

README.md

@@ -11,4 +11,18 @@ then
 `jupyter-book build ./`
 to build the current working directory into a jupyter-book.
 
-The html is in the folder `_build\html\` and you can preview the book by opening the file `_build\html\index.html`
+The html is in the folder `_build\html\` and you can preview the book by opening the file `_build\html\index.html` in your browser, using VSCode's preview functionality (recommended), or running a the file via a browser executable in command line.
+
+Following this, to deploy your build to the github page, we will be using the `ghp-import` library.
+
+Install using `pip install ghp-import`
+
+Now run `ghp-import -n -p -f -b BRANCHNAME _build/html`
+
+**NOTE: This is a destructive action. It will overwrite any branch named BRANCHNAME and assume it is 100% derivative**
+
+The -b tag should be followed by the branch which you wish to deploy the html to. By default it is gh-pages. If you're wishing to non-destructively test a local build, push to a separate branch name, and change the branch referenced for the github page in the settings, allowing for a quick revert to the gh-pages branch.
+
+The -n tag indicates building without Jekyll
+
+The -p and -f tags indicate force pushing this branch after committing it.