Fix typos and improve grammar in documentation (#1769)

* typos create-api.md

* typos _eth_getunclebyblockhashandindex-description.mdx

* typos _eth_getunclebyblocknumberandindex-description.mdx

* typos authenticate-with-jwt.md

Author: Dimitrolito

developer-tools/dashboard/get-started/create-api.md

@@ -20,7 +20,7 @@ For more information, see to the [Infura pricing page](https://www.infura.io/pri
 Infura allows you to enable multiple network endpoints and expansion APIs for your API key. If calls are
 made to a disabled network or service, then all requests to that network or service will fail.
 
-To keep your account secure and cost effective, add only the necessary endpoints, as some have usage
+To keep your account secure and cost-effective, add only the necessary endpoints, as some have usage
 limits or charges based on request volume.
 
 To create an API key:

services/reference/_partials/_eth_getunclebyblockhashandindex-description.mdx

@@ -1 +1 @@
-Returns information about a uncle of a block given the block hash and the uncle index position.
+Returns information about an uncle of a block given the block hash and the uncle index position.

services/reference/_partials/_eth_getunclebyblocknumberandindex-description.mdx

@@ -1 +1 @@
-Returns information about a uncle of a block given the block number and the uncle index position.
+Returns information about an uncle of a block given the block number and the uncle index position.

services/tutorials/ethereum/authenticate-with-jwt.md

@@ -255,7 +255,7 @@ Block number: 0x61fc48
 :::tip
 
 This script:
-1. Generates a JWT with a 1 hour expiry that is only valid on `infura.io`.
+1. Generates a JWT with a 1-hour expiry that is only valid on `infura.io`.
 2. Applies this JWT to form the header of a `getBlockNumber` call.
 3. Submits the API call.