doc: rephrase dynamic import() description

doc: rephrase dynamic import() description · nodejs/node@e9cb986

Original file line number	Diff line number	Diff line change
`@@ -334,8 +334,9 @@ fs.readFileSync === readFileSync;`
`334`	`334`
`335`	`335`	## `import()` expressions
`336`	`336`
`337`		-[Dynamic `import()`][] is supported in both CommonJS and ES modules. In CommonJS
`338`		`-modules it can be used to load ES modules.`
	`337`	+[Dynamic `import()`][] provides an asynchronous way to import modules. It is
	`338`	`+supported in both CommonJS and ES modules, and can be used to load both CommonJS`
	`339`	`+and ES modules.`
`339`	`340`
`340`	`341`	## `import.meta`
`341`	`342`