set_first(conf, type, opt, val) {
		let sid = null;

		this.sections(conf, type, s => {
			sid ??= s['.name'];
		});

		return this.set(conf, sid, opt, val);
	}
Sets the value of the given option within the first found section
of the given configuration matching the specified type or within
the first section of the entire config when no type has is specified.

If either config, type or option is null, or if `option` begins
with a dot, the function will do nothing.

@param {string} conf
The name of the configuration to set the option value in.

@param {string} [type]
The type of the first section to find. If it is `null`, the first
section of the entire config is written to, otherwise the first
section matching the given type is used.

@param {string} opt
The option name to set the value for.

@param {null|string|string[]} val
The option value to set. If the value is `null` or an empty string,
the option will be removed, otherwise it will be set or overwritten
with the given value.