doc: streamline errors.md introductory material · nodejs/node@06ac81e

Applications running in Node.js will generally experience four categories of

errors:

- Standard JavaScript errors such as:

- {EvalError} : thrown when a call to `eval()` fails.

- {SyntaxError} : thrown in response to improper JavaScript language

syntax.

- {RangeError} : thrown when a value is not within an expected range

- {ReferenceError} : thrown when using undefined variables

- {TypeError} : thrown when passing arguments of the wrong type

- {URIError} : thrown when a global URI handling function is misused.

- Standard JavaScript errors such as {EvalError}, {SyntaxError}, {RangeError},

{ReferenceError}, {TypeError}, and {URIError}.

- System errors triggered by underlying operating system constraints such

as attempting to open a file that does not exist, attempting to send data

over a closed socket, etc;

- And User-specified errors triggered by application code.

- `AssertionError`s are a special class of error that can be triggered whenever

as attempting to open a file that does not exist or attempting to send data

over a closed socket.

- User-specified errors triggered by application code.

- `AssertionError`s are a special class of error that can be triggered when

Node.js detects an exceptional logic violation that should never occur. These

are raised typically by the `assert` module.