update admonition text'

Author: mmcky

lectures/ar1_processes.md

@@ -23,7 +23,7 @@ kernelspec:
 ```{admonition} Migrated lecture
 :class: warning
 
-We have moved this lecture from [Intermediate Quantitative Economics with Python](https://python.quantecon.org/intro.html).
+This lecture has moved from our [Intermediate Quantitative Economics with Python](https://python.quantecon.org/intro.html) lecture series and is now a part of [A First Course in Quantitative Economics](https://intro.quantecon.org/intro.html).
 ```
 
 ```{index} single: Autoregressive processes