Update COC settings

- Add ccls
- Update coc-spell-checker
- Update theme
diff --git a/modules/neovim/coc/snippets/markdown.snippets b/modules/neovim/coc/snippets/markdown.snippets
index ce82400..f30c2c7 100644
--- a/modules/neovim/coc/snippets/markdown.snippets
+++ b/modules/neovim/coc/snippets/markdown.snippets
@@ -81,6 +81,10 @@
 X\sim N(${1:mean}, ${2:variance})${0}
 endsnippet
 
+snippet poissondistribution "A poisson distribution" i
+X\sim \text{Po}(${1:\lambda})${0}
+endsnippet
+
 snippet 2x2matrix "A 2 by 2 matrix" i
 \begin{bmatrix} ${1} & ${2} \\\\ ${3} & ${4} \end{bmatrix}${0}
 endsnippet
@@ -104,3 +108,15 @@
 snippet ne "Not equal to" i
 \not =
 endsnippet
+
+snippet arsinh "Arsinh" i
+\text{arsinh}
+endsnippet
+
+snippet artanh "Artanh" i
+\text{artanh}
+endsnippet
+
+snippet arcosh "Arcosh" i
+\text{arcosh}
+endsnippet