internal/history: document Go 1.15.2 and Go 1.14.9

For golang/go#41292.
For golang/go#41293.

Change-Id: Ieddb8fc000c49e14e897d5e7077f51cd0754a368
Reviewed-on: https://go-review.googlesource.com/c/website/+/253740
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alexander Rakoczy <alex@golang.org>
diff --git a/internal/history/release.go b/internal/history/release.go
index c151422..3124046 100644
--- a/internal/history/release.go
+++ b/internal/history/release.go
@@ -31,6 +31,19 @@
 // It contains entries for releases of Go 1.9 and newer.
 // Older releases are listed in doc/devel/release.html.
 var Releases = map[GoVer]Release{
+	{1, 15, 2}: {
+		Date: Date{2020, 9, 9},
+
+		Components: []template.HTML{"the compiler", "runtime", "documentation", "the <code>go</code> command"},
+		Packages:   []string{"net/mail", "os", "sync", "testing"},
+	},
+	{1, 14, 9}: {
+		Date: Date{2020, 9, 9},
+
+		Components: []template.HTML{"the compiler", "linker", "runtime", "documentation"},
+		Packages:   []string{"net/http", "testing"},
+	},
+
 	{1, 15, 1}: {
 		Date:     Date{2020, 9, 1},
 		Security: true,