message: Highlight string concatenation '#' in bibtex mode
diff: "end": "(?=[,}])",
  "name": "meta.key-assignment.bibtex",
  "patterns": [
  + {
  + "include": "#string_var"
  + },
  {
  "include": "#string_content"
  },
  "end": "(?=[,)])",
  "name": "meta.key-assignment.bibtex",
  "patterns": [
  + {
  + "include": "#string_var"
  + },
  {
  "include": "#string_content"
  },
  }
  ]
  },
  + "string_var": {
  + "match": "(#)?\\s*([a-zA-Z]+)\\s*(#)?",
  + "captures": {
  + "1": {
  + "name": "keyword.operator.bibtex"
  + },
  + "2": {
  + "name": "support.variable.bibtex"
  + },
  + "3": {
  + "name": "keyword.operator.bibtex"
  + }
  + }
  + },
  "string_content": {
  "patterns": [
  {
  "name": "punctuation.definition.string.begin.bibtex"
  }
  },
  - "end": "\\}(?=,?\\s*\\}?\\s*\\n)",
  + "end": "(\\})(?=(?:,?\\s*\\}?\\s*\\n)|(?:\\s*#))",
  "endCaptures": {
  - "0": {
  + "1": {
  "name": "punctuation.definition.string.end.bibtex"
  }
  },
  "name": "punctuation.definition.string.begin.bibtex"
  }
  },
  - "end": "\"(?=,?\\s*\\}?\\s*\\n)",
  + "end": "\"(?=(?:,?\\s*\\}?\\s*\\n)|(?:\\s*#))",
  "endCaptures": {
  "0": {
  "name": "punctuation.definition.string.end.bibtex"
  