readme add link to tag image pdf

Readme.md adds link to tag image pdf and the original tag images directory.

examples/pose-apriltag/readme.md

@@ -6,7 +6,9 @@ In order to run this example, a T265 is required.
 
 [Apriltags](https://april.eecs.umich.edu/software/apriltag) are fiducial markers that have been designed to be easily detected in images (other fiducial markers include QR codes and ARTags). Once detected, these markers can be used for a variety of applications.
 
-This sample demonstrates how to detect the pose of a Apriltag of a known size that is visible in a T265 fisheye frame relative to the camera. Apriltags are detected on every 6th frame (at 5Hz). The sample uses `36h11` tags, though it can be easily modified to work with any tag supported by the Apriltag library.
+This sample demonstrates how to detect the pose of a Apriltag of a known size that is visible in a T265 fisheye frame relative to the camera. Apriltags are detected on every 6th frame (at 5Hz). The sample uses `36h11` tags, though it can be easily modified to work with any tag supported by the Apriltag library. 
+
+A sample `36h11` image pdf can be downloaded [here](./tag36_11_00000_out180mm_in144mm.pdf), and other tag images can be found [here](https://github.com/AprilRobotics/apriltag-imgs). 
 
 ## Dependency