add `+=` to assignment operators
{
"comment": "assignment operators",
"name": "keyword.operator.assignment.rust",
- "match": "(-=|\\*=|/=|%=|\\^=|&=|\\|=|<<=|>>=)"
+ "match": "(\\+=|-=|\\*=|/=|%=|\\^=|&=|\\|=|<<=|>>=)"
},
{
"comment": "single equal",
