Fix some documentation links

Changes needed as a result of migration of documentation out of main extension's README and off GitHub

Author: gjsjohnmurray

README.md

@@ -119,7 +119,7 @@ The 'star' button that appears when you hover over the row lets you add the serv
 
 Learn more about `isfs` and `isfs-readonly` folders in the [InterSystems ObjectScript for VS Code documentation](https://intersystems-community.github.io/vscode-objectscript/serverside).
 
-> If you are already doing client-side editing of your code (for example, managing it with Git), be sure you understand the consequences of also doing server-side editing using `isfs`. The ObjectScript extension's [README](https://marketplace.visualstudio.com/items?itemName=intersystems-community.vscode-objectscript) outlines the differences between client-side and server-side editing. If in doubt, limit yourself to `isfs-readonly` by only using the eye icon.
+> If you are already doing client-side editing of your code (for example, managing it with Git), be sure you understand the consequences of also doing server-side editing using `isfs`. The [documentation](https://docs.intersystems.com/components/csp/docbook/DocBook.UI.Page.cls?KEY=GVSCO_intro) outlines the differences between client-side and server-side editing. If in doubt, limit yourself to `isfs-readonly` by only using the eye icon.
 
 ## The 'Current' Folder