doc: improve DEP0090 text

Edit text for "DEP0090: Invalid GCM authentication tag lengths" for
clarity and branding. Invalid langths are "invalid" rather than
"considered invalid". Refer to "Node.js v11.0.0" rather than "node
v11.0.0".

PR-URL: https://github.com/nodejs/node/pull/28097


Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Beth Griggs <Bethany.Griggs@uk.ibm.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>