Spelling/grammar changes to Strategy doc

Check List

[ ] Add Labels
- For software RFCs: add the "rfc-community-review" and the appropriate software project name (such as "Data Store") labels. When the RFC impacts multiple DCP software projects, then the "Architecture" label MUST be the project name. If uncertain about the appropriate project name, then Ask a PM on the HCA #dcp-project-mgmt slack channel
- For governance RFCs: Add the "rfc-community-review" and the "Governance" labels.
[ ] April 1: Community Review Last Call
[ ] Request review on Slack channel #dcp.
[ ] Send an FYI to the appropriate HumanCellAtlas Slack channel. Include a link to the RFC pull request and the last call deadline.
- For Software RFCs: #tech-architecture
- For Governance RFCs: #dcp-project-mgmt
[ ] Shepherd: Add RFC as an agenda item to next meeting:
- For Software RFCS: DCP Architecture meeting
- For Governance RFCs: DCP PM meeting
[ ] Shepherd: Summarize the review discussion for the Approvers in the top-level summary comment in the RFC pull request

[ ] Replace "rfc-community-review" with "rfc-approved"
[ ] Rename the RFC from 0000-my-feature.md to ####-my-feature.md (with leading zeros) where #### is the next available RFC number
[ ] Create a link between the approved RFC and its pull request by updating the DCP PR section in the RFC template and pushing the commit.

Once all tasks are complete merge the PR in and Announce the approval in #dcp.