createSubscription (#4)

* implemented SubscriptionManager class and createSubscription method

* regenerated package-lock.json

* added recompilation in separate command

* regenerated package-lock.json

* added env var during hardhat compilation

* ran prettier

* fixed corrupted package-lock.json

.github/workflows/test-converage.yaml

@@ -8,6 +8,8 @@ on:
 jobs:
   coverage:
     runs-on: ubuntu-latest
+    env:
+      DEBUG_TEST_SETUP: true
 
     steps:
       - name: Checkout repository

.github/workflows/test.yaml

@@ -8,6 +8,8 @@ on:
 jobs:
   tests:
     runs-on: ubuntu-latest
+    env:
+      DEBUG_TEST_SETUP: true
 
     steps:
       - name: Checkout repository

README.md

@@ -1,3 +1,19 @@
 # functions-toolkit
 
 An NPM package with collection of functions that can be used for working with Chainlink Functions.
+
+## Functions Billing Subscription Management
+
+The `SubscriptionManager` class is used to manage the billing subscription used to pay for Functions requests. Create an instance of this class by passing an instance of the [Ethers.js Signer class](https://docs.ethers.org/v5/api/signer/#Signer) with a connected provider and the address of the [Functions Oracle proxy and the Functions Oracle Registry proxy](https://docs.chain.link/chainlink-functions/supported-networks) contracts on the desired network.
+
+> const subscriptionManager = new SubscriptionManager(
+> signer: [Signer](https://docs.ethers.org/v5/api/signer/#Signer),
+> [functionsOracleProxyAddress](https://docs.chain.link/chainlink-functions/supported-networks): string,
+> [functionsOracleRegistryProxyAddress](https://docs.chain.link/chainlink-functions/supported-networks): string
+> )
+
+### Create Subscription
+
+> subscriptionManager.createSubscription() => Promise\<BigInt>
+
+Creates a new Functions billing subscription using the Functions Oracle Registry contract and returns the subscription ID.