mergeMetaTags()function

mergeMetaTags(current: MetaTags | undefined, next: MetaTags | undefined): MetaTags | undefined

Param	Type
`current`	`MetaTags`	The existing tags.
`next`	`MetaTags`	The new tags to merge on top.

Return
`MetaTags \| undefined`	The merged tags, or `undefined` if both inputs were unset.

Merge two sets of meta <meta> tags, with next taking precedence over current.