doc: rename x509.extKeyUsage to x509.keyUsage

doc: rename x509.extKeyUsage to x509.keyUsage · nodejs/node@fd61588

Original file line number	Diff line number	Diff line change
`@@ -2690,16 +2690,6 @@ added: v15.6.0`
`2690`	`2690`	`Checks whether the public key for this certificate is consistent with`
`2691`	`2691`	`the given private key.`
`2692`	`2692`
`2693`		-### `x509.extKeyUsage`
`2694`		`-`
`2695`		`-<!-- YAML`
`2696`		`-added: v15.6.0`
`2697`		`--->`
`2698`		`-`
`2699`		`-* Type: {string\[]}`
`2700`		`-`
`2701`		`-An array detailing the key extended usages for this certificate.`
`2702`		`-`
`2703`	`2693`	### `x509.fingerprint`
`2704`	`2694`
`2705`	`2695`	`<!-- YAML`
`@@ -2791,6 +2781,16 @@ added: v15.9.0`
`2791`	`2781`	The issuer certificate or `undefined` if the issuer certificate is not
`2792`	`2782`	`available.`
`2793`	`2783`
	`2784`	+### `x509.keyUsage`
	`2785`	`+`
	`2786`	`+<!-- YAML`
	`2787`	`+added: v15.6.0`
	`2788`	`+-->`
	`2789`	`+`
	`2790`	`+* Type: {string\[]}`
	`2791`	`+`
	`2792`	`+An array detailing the key extended usages for this certificate.`
	`2793`	`+`
`2794`	`2794`	### `x509.publicKey`
`2795`	`2795`
`2796`	`2796`	`<!-- YAML`