Update README.md

[ifeanyidavid]

• Fixed EvaluationError that was caused by dangling comma at the end of the expression string.

   at async loadESM (node:internal/process/esm_loader:28:7)
    at async handleMainPromise (node:internal/modules/run_main:113:12) {
  name: 'EvaluationError',
  message: 'Unable to evaluate expression: Value expected (char 148)',
  type: 'SyntaxError',
  _baseError: SyntaxError: Value expected (char 148)
      at createSyntaxError (file:///project/workspace/node_modules/mathjs/lib/esm/expression/parse.js:1608:17)
      at parseEnd (file:///project/workspace/node_modules/mathjs/lib/esm/expression/parse.js:1575:13)
      at parseParentheses (file:///project/workspace/node_modules/mathjs/lib/esm/expression/parse.js:1562:12)
      at parseNumber (file:///project/workspace/node_modules/mathjs/lib/esm/expression/parse.js:1535:12)
      at parseObject (file:///project/workspace/node_modules/mathjs/lib/esm/expression/parse.js:1517:12)
      at parseMatrix (file:///project/workspace/node_modules/mathjs/lib/esm/expression/parse.js:1449:12)
      at parseString (file:///project/workspace/node_modules/mathjs/lib/esm/expression/parse.js:1343:12)
      at parseSymbol (file:///project/workspace/node_modules/mathjs/lib/esm/expression/parse.js:1241:12)
      at parseCustomNodes (file:///project/workspace/node_modules/mathjs/lib/esm/expression/parse.js:1214:12)
      at parseLeftHandOperators (file:///project/workspace/node_modules/mathjs/lib/esm/expression/parse.js:1138:12) {
    char: 148
  }
}

• Corrected the duplicate failure_message key in the context.