message: For maths snippets, use $0 as the placeholder for the body part
  This is related to
diff: {
  "begin":{
  "command":"begin",
  - "snippet":"begin{${1:env}}\n\t$2\n\\\\end{${1:env}}",
  + "snippet":"begin{${1:env}}\n\t$0\n\\\\end{${1:env}}",
  "detail":"begin a new environment"
  },
  "lrparen":{
  "command":"left(",
  - "snippet":"left(${1}\\right)${0}",
  + "snippet":"left($0\\right)",
  "detail":"\\left( ... \\right)"
  },
  "lrbrack":{
  "command":"left[",
  - "snippet":"left[${1}\\right]${0}",
  + "snippet":"left[$0\\right]",
  "detail":"\\left[ ... \\right]"
  },
  "lrcurly":{
  "command":"left\\{",
  - "snippet":"left\\{${1}\\right\\\\}${0}",
  + "snippet":"left\\{$0\\right\\\\}",
  "detail":"\\left\\{ ... \\right\\}"
  },
  "frame": {
  },
  "latexinlinemath":{
  "command":"(",
  - "snippet":"(${1}\\)${0}",
  + "snippet":"(${0}\\)",
  "detail":"inline math \\( ... \\)"
  },
  "latexdisplaymath":{
  "command":"[",
  - "snippet":"[${1}\\]${0}",
  + "snippet":"[$0\\]",
  "detail":"display math \\[ ... \\]"
  },
  "curlybrackets":{
  "command":"{",
  - "snippet":"{${1}\\\\}${0}",
  + "snippet":"{$0\\\\}",
  "detail":"curly brackets \\{ ... \\}"
  },
  "title":{
  