cleanup(tex): these are all also rather specific snippets

It should suffice to have a snippet for subscript and one for
superscript. We don't need to have a snippet for each possible
superscript.

UltiSnips/tex.snippets

@@ -217,46 +217,6 @@ endsnippet
 # MATH #
 ########
 
-snippet "([a-zA-Z])MM"  "^m" wr
-`!p snip.rv = match.group(1)`^{m}
-endsnippet
-
-snippet "([a-zA-Z])NN"  "^n" wr
-`!p snip.rv = match.group(1)`^{n}
-endsnippet
-
-snippet "([a-zA-Z])II"  "^i" wr
-`!p snip.rv = match.group(1)`^{i}
-endsnippet
-
-snippet "([a-zA-Z])KK"  "^k" wr
-`!p snip.rv = match.group(1)`^{k}
-endsnippet
-
-snippet "([a-zA-Z])JJ"  "^j" wr
-`!p snip.rv = match.group(1)`^{j}
-endsnippet
-
-snippet "([a-zA-Z])mm"  "_m" wr
-`!p snip.rv = match.group(1)`_{m}
-endsnippet
-
-snippet "([a-zA-Z])nn"  "_n" wr
-`!p snip.rv = match.group(1)`_{n}
-endsnippet
-
-snippet "([a-zA-Z])ii"  "_i" wr
-`!p snip.rv = match.group(1)`_{i}
-endsnippet
-
-snippet "([a-zA-Z])kk"  "_k" wr
-`!p snip.rv = match.group(1)`_{k}
-endsnippet
-
-snippet "([a-zA-Z])jj"  "_j" wr
-`!p snip.rv = match.group(1)`_{j}
-endsnippet
-
 snippet cc "subset" w
 \subset 
 endsnippet