Update changelog for 7.0 release

[mfedderly]

No description provided.

[twelch]

Consider clarifying that Typescript users will need to migrate their code to use @types/geojson directly as its type definitions are not re-exported by turf. That seems to be a common question/comment that comes up with people using the 7.x prereleases.

[mfedderly]

Consider clarifying that Typescript users will need to migrate their code to use @types/geojson also. That seems to be a common question/comment that comes up with people using the 7.x prereleases.

- Move to @types/geojson package instead of declaring our own (#2158) <- this is the first entry under breaking changes, is there more wording you want to add?

[twelch]

Thanks @mfedderly , yea I read that first entry as describing turfs internal change. How about adding "base geojson type definitions are no longer re-rexported by Turf. Typescript users will need to import them from @types/geojson directly"