[x/blog] content: add go1.15.article

For golang/go#27155

Change-Id: I6c0a2a7b9293a39393192920c3625b6f09d77e0a
Reviewed-on: https://go-review.googlesource.com/c/blog/+/247406
Reviewed-by: Carlos Amedee <[email protected]>
X-Blog-Commit: 3841cf6a3ea0effaf63edb48a2cc0973c56ce756

Author: toothrot

blog/content/go1.15.article

@@ -0,0 +1,26 @@
+# Go 1.15 is released
+11 Aug 2020
+Summary: Go 1.15 adds a new linker, X.509 changes, runtime improvements, compiler improvements, GOPROXY improvements, and more.
+
+Alex Rakoczy
+
+##
+
+Today the Go team is very happy to announce the release of Go 1.15. You can get it from the [download page](https://golang.org/dl).
+
+Some of the highlights include:
+
+  - [Substantial improvements to the Go linker](https://golang.org/doc/go1.15#linker)
+  - [Improved allocation for small objects at high core counts](https://golang.org/doc/go1.15#runtime)
+  - [X.509 CommonName deprecation](https://golang.org/doc/go1.15#commonname)
+  - [GOPROXY supports skipping proxies that return errors](https://golang.org/doc/go1.15#go-command)
+  - [New embedded tzdata package](https://golang.org/doc/go1.15#time/tzdata)
+  - [A number of Core Library improvements](https://golang.org/doc/go1.15#library)
+
+For the complete list of changes and more information about the improvements above, see the [**Go 1.15 release notes**](https://golang.org/doc/go1.15).
+
+We want to thank everyone who contributed to this release by writing code, filing bugs, providing feedback, and/or testing the beta and release candidates.
+Your contributions and diligence helped to ensure that Go 1.15 is as stable as possible.
+That said, if you notice any problems, please [file an issue](https://golang.org/issue/new).
+
+We hope you enjoy the new release!