rest file
  PsiElement(EXPLISIT_MARKUP_START)('.. ')
  RestReferenceTarget:REFERENCE
    PsiElement(SUBSTITUTION)('|caution|')
  PsiElement(WHITESPACE)(' ')
  RestDirective:DIRECTIVE_BLOCK
    PsiElement(DIRECTIVE)('image::')
    PsiElement(LINE)(' warning.png')
    PsiElement(WHITESPACE)('\n    ')
    PsiElement(FIELD)(':alt:')
    PsiElement(LINE)(' Warning!')