_content/blog: add acknowledgements to PGO blog posts

Change-Id: I061e590a77153d02deb5d9648fe58069bd9de5b8
Reviewed-on: https://go-review.googlesource.com/c/website/+/595035
Reviewed-by: Eli Bendersky <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>

Author: prattmic

_content/blog/pgo-preview.md

@@ -217,3 +217,7 @@ Please send us your feedback!
 PGO is still in preview and we'd love to hear about anything that is difficult to use, doesn't work correctly, etc.
 Please file issues at [go.dev/issue/new](/issue/new).
 
+## Acknowledgements
+
+Adding profile-guided optimization to Go is a team effort, and I particularly want to call out the contributions from Raj Barik and Jin Lin at Uber, and Cherry Mui and Austin Clements at Google.
+This kind of cross-community collaboration is a key part of making Go great.

_content/blog/pgo.md

@@ -554,3 +554,7 @@ PGO (and most compiler optimizations) generally yield their benefit in the aggre
 Inlining and devirtualization are the two PGO-driven optimizations available in Go 1.21, but as we’ve seen, these often unlock additional optimizations.
 In addition, future versions of Go will continue to improve PGO with additional optimizations.
 
+## Acknowledgements
+
+Adding profile-guided optimization to Go has been a team effort, and I particularly want to call out the contributions from Raj Barik and Jin Lin at Uber, and Cherry Mui and Austin Clements at Google.
+This kind of cross-community collaboration is a key part of making Go great.