Move move .emacs.d out of configs/shared

Moving all of my Emacs-related files into their own directory at the root of
this repository.

emacs/.emacs.d/snippets/c-mode/.yas-parents

@@ -0,0 +1 @@
+text-mode

emacs/.emacs.d/snippets/c-mode/stdio

@@ -0,0 +1,5 @@
+# -*- mode: snippet -*-
+# name: <stdio.h>
+# key: sio
+# --
+#include <stdio.h>

emacs/.emacs.d/snippets/c-mode/stdlib

@@ -0,0 +1,5 @@
+# -*- mode: snippet -*-
+# name: <stdlib.h>
+# key: slb
+# --
+#include <stdlib.h>

emacs/.emacs.d/snippets/c-mode/struct

@@ -0,0 +1,7 @@
+# -*- mode: snippet -*-
+# name: struct
+# key: struct
+# --
+typedef struct $1 {
+  $2
+} $1_t;