Fixes dead links

README.md

@@ -2,9 +2,10 @@
 
 This repository stores USGS CSM compliant camera models and the associated
 plugins.  These camera models are compliant with the [Community Sensor
-Model](spec) and can be utilized within any application supporting the CSM.
+Model](https://github.com/sminster/csm) and can be utilized within any application supporting the CSM.
 
-The CSM requires associated [Image Support Data]().  This data is primarily
+The CSM requires associated Image Support Data.  This data is primarily
 provided by the NASA Navigation and Ancillary Information (NAIF) SPICE system.
-We provide a seperate CSM-SpiceISD library to interface with the NAIF Spice
+We provide a seperate
+[CSM-SpiceISD](https://github.com/USGS-Astrogeology/CSM-SpiceISD) library to interface with the NAIF Spice
 functionality and provide a standard ISD file.