Add yasnippet snippets for latex

- f1 adds a frac 1/ something
- prob adds a section and align*

.emacs.d/snippets/latex-mode/f1

@@ -0,0 +1,5 @@
+# -*- mode: snippet; require-final-newline: nil -*-
+# name: frac1
+# key: f1
+# --
+\frac{1}{$1}$0

.emacs.d/snippets/latex-mode/problem

@@ -0,0 +1,8 @@
+# -*- mode: snippet; require-final-newline: nil -*-
+# name: problem
+# key: prob
+# --
+\sub$1section{}
+\begin{align*}
+  $0
+\end{align*}