Add missing release aliases

These were previously missed because the front matter validation tests
did not descend into the individual directories of posts with colocated
assets.

Author: senekor

content/Rust-1.12/index.md

@@ -2,7 +2,10 @@
 path = "2016/09/29/Rust-1.12"
 title = "Announcing Rust 1.12"
 authors = ["The Rust Core Team"]
-aliases = ["2016/09/29/Rust-1.12.html"]
+aliases = [
+    "2016/09/29/Rust-1.12.html",
+    "releases/1.12.0",
+]
 
 [extra]
 release = true

content/Rust-1.13/index.md

@@ -2,7 +2,10 @@
 path = "2016/11/10/Rust-1.13"
 title = "Announcing Rust 1.13"
 authors = ["The Rust Core Team"]
-aliases = ["2016/11/10/Rust-1.13.html"]
+aliases = [
+    "2016/11/10/Rust-1.13.html",
+    "releases/1.13.0",
+]
 
 [extra]
 release = true

content/Rust-1.30.0/index.md

@@ -2,7 +2,10 @@
 path = "2018/10/25/Rust-1.30.0"
 title = "Announcing Rust 1.30"
 authors = ["The Rust Core Team"]
-aliases = ["2018/10/25/Rust-1.30.0.html"]
+aliases = [
+    "2018/10/25/Rust-1.30.0.html",
+    "releases/1.30.0",
+]
 
 [extra]
 release = true

content/Rust-1.60.0/index.md

@@ -2,7 +2,10 @@
 path = "2022/04/07/Rust-1.60.0"
 title = "Announcing Rust 1.60.0"
 authors = ["The Rust Release Team"]
-aliases = ["2022/04/07/Rust-1.60.0.html"]
+aliases = [
+    "2022/04/07/Rust-1.60.0.html",
+    "releases/1.60.0",
+]
 
 [extra]
 release = true