Fix typo in introduction.md

The sentence:

> ...along with **guarantee** speed at any scale...

Should read:

> ...along with **guaranteed** speed at any scale...

Author: ericmutta

articles/cosmos-db/introduction.md

@@ -18,7 +18,7 @@ adobe-target: true
 
 Today's applications are required to be highly responsive and always online. To achieve low latency and high availability, instances of these applications need to be deployed in datacenters that are close to their users. Applications need to respond in real time to large changes in usage at peak hours, store ever increasing volumes of data, and make this data available to users in milliseconds.
 
-Azure Cosmos DB is a fully managed NoSQL and relational database for modern app development. Azure Cosmos DB offers single-digit millisecond response times, automatic and instant scalability, along with guarantee speed at any scale. Business continuity is assured with [SLA-backed](https://azure.microsoft.com/support/legal/sla/cosmos-db) availability and enterprise-grade security.
+Azure Cosmos DB is a fully managed NoSQL and relational database for modern app development. Azure Cosmos DB offers single-digit millisecond response times, automatic and instant scalability, along with guaranteed speed at any scale. Business continuity is assured with [SLA-backed](https://azure.microsoft.com/support/legal/sla/cosmos-db) availability and enterprise-grade security.
 
 App development is faster and more productive thanks to: