Replace non-link to company call agenda

Why is this change being made?

With the recent changes to the Company Call content and frequency, the agenda is gone now, and is replaced by an Announcements document (and #company-announcements in Slack). Change the name and make this a link for easy access

Does this MR meet the acceptance criteria?

Assign to DRI

• Did you assign this change to the correct DRI of the page or information you are changing?

Conformity

• Added description to this MR explaining the reasons for the proposed change, per say-why-not-just-what