Miscellaneous fixes in AMM README (#2606)

## Motivation

Small grammar error in AMM README

## Proposal

Fix it

## Test Plan

CI

## Release Plan

- Nothing to do / These changes follow the usual release cycle.

examples/amm/README.md

@@ -185,7 +185,7 @@ Note: The above mutation has to be performed from `http://localhost:8080`.
 Before performing any operation we need to provide liquidity to it, so we will use the `AddLiquidity` operation,
 navigate to the URL you get by running `echo "http://localhost:8080/chains/$CHAIN_1/applications/$AMM_APPLICATION_ID"`.
 
-To perform `AddLiquidity` operation:
+To perform the `AddLiquidity` operation:
 
 ```gql,uri=http://localhost:8080/chains/$CHAIN_1/applications/$AMM_APPLICATION_ID
 mutation {
@@ -209,7 +209,7 @@ mutation {
 
 Note: The above mutation has to be performed from `http://localhost:8080`.
 
-To perform `Swap` operation, navigate to the URL you get by running `echo "http://localhost:8080/chains/$CHAIN_2/applications/$AMM_APPLICATION_ID"` and
+To perform the `Swap` operation, navigate to the URL you get by running `echo "http://localhost:8080/chains/$CHAIN_2/applications/$AMM_APPLICATION_ID"` and
 perform the following mutation:
 
 ```gql,uri=http://localhost:8080/chains/$CHAIN_2/applications/$AMM_APPLICATION_ID

examples/amm/src/lib.rs

@@ -189,7 +189,7 @@ Note: The above mutation has to be performed from `http://localhost:8080`.
 Before performing any operation we need to provide liquidity to it, so we will use the `AddLiquidity` operation,
 navigate to the URL you get by running `echo "http://localhost:8080/chains/$CHAIN_1/applications/$AMM_APPLICATION_ID"`.
 
-To perform `AddLiquidity` operation:
+To perform the `AddLiquidity` operation:
 
 ```gql,uri=http://localhost:8080/chains/$CHAIN_1/applications/$AMM_APPLICATION_ID
 mutation {
@@ -213,7 +213,7 @@ mutation {
 
 Note: The above mutation has to be performed from `http://localhost:8080`.
 
-To perform `Swap` operation, navigate to the URL you get by running `echo "http://localhost:8080/chains/$CHAIN_2/applications/$AMM_APPLICATION_ID"` and
+To perform the `Swap` operation, navigate to the URL you get by running `echo "http://localhost:8080/chains/$CHAIN_2/applications/$AMM_APPLICATION_ID"` and
 perform the following mutation:
 
 ```gql,uri=http://localhost:8080/chains/$CHAIN_2/applications/$AMM_APPLICATION_ID