add links to change log PRs (#1017)

Author: bashbaug

api/appendix_e.asciidoc

@@ -564,9 +564,9 @@ Changes from *v3.0.12*:
 
 Changes from *v3.0.13*:
 
-  * Corrected the precision for `cross` and `dot` to be based on `HALF_EPSILON` in `cl_khr_fp16`, see GitHub #893.
-  * Added a context query for command-buffers to `cl_khr_command_buffer`, see GitHub #899.
-  * Updated the semaphore wait and signal rules for binary semaphores in `cl_khr_semaphore`, see GitHub #882.
-  * Removed redundant error conditions from `cl_khr_external_semaphore` and `cl_khr_external_memory`, see GitHub #903 and #904.
+  * Corrected the precision for `cross` and `dot` to be based on `HALF_EPSILON` in `cl_khr_fp16`, see {khronos-opencl-pr}/893[#893].
+  * Added a context query for command-buffers to `cl_khr_command_buffer`, see {khronos-opencl-pr}/899[#899].
+  * Updated the semaphore wait and signal rules for binary semaphores in `cl_khr_semaphore`, see {khronos-opencl-pr}/882[#882].
+  * Removed redundant error conditions from `cl_khr_external_semaphore` and `cl_khr_external_memory`, see {khronos-opencl-pr}/903[#903] and {khronos-opencl-pr}/904[#904].
   * Added new extension:
       ** `cl_khr_command_buffer_multi_device` (provisional)

config/opencl.asciidoc

@@ -4,6 +4,9 @@
 
 // Attributes that are shared by OpenCL specifications.
 
+:khronos-opencl-repo: https://github.com/KhronosGroup/OpenCL-Docs
+:khronos-opencl-pr: {khronos-opencl-repo}/pull
+
 :blank: pass:[ +]
 :pp: ++
 :cpp: pass:[C++]