Draft deeper guidance to learner in lesson body until line 239

Author: elPiablo

pages/lessons/projects/3.mdx

@@ -31,21 +31,22 @@ differentiate between different levels or categories in that service. Think of s
 streaming services out there such as Netflix, Disney+, etc. Some have different levels
 of access depending on the subscription. We want to let users access different
 services depending on the NFT they mint and own.
+I'M NOT AT ALL SURE WHAT WE ARE BUILDING..... MAKE SURE WE ADD THAT WE'LL BE INHERITING A FEW MORE OZ CONTRACTS ThIS TIME. MAYBE A NUDGE TO LEARNER TO READ SOME OF THE OZ CODE?
 
 ![1_diagram.png](/assets/lessons/3/1_diagram.png)
 
 ## First things first 👷‍♂️
 
 Before we start coding, we need to create our project template. We are going to follow
 the same steps as in previous lessons. Using our package manager (npm, yarn,
-etc) we create a Hardhat project and remove unnecessary files.
+etc)WE ARE ONLY USING ONE we create a Hardhat project and remove unnecessary files.
 
 If you’ve done our previous lesson, it’s the exact same process. Make a note of
 remembering these steps and what they do, for we will use them a lot in
 the future.
 
-Let’s first open a console and cd into our `d_d_academy` folder, or create it
-first if you don't have it. Then let's create a folder for our NFT project:
+Let’s first open a console and `cd` into our `d_d_academy` folder, or create it
+first if you don't have it. Then let's create a folder for our NFT project and make sure to `cd` into it too:
 
 ```bash
 ## (OPTIONAL) create a folder for our D_D Academy projects
@@ -100,22 +101,22 @@ install them manually with:
 npm install --save-dev hardhat @nomicfoundation/hardhat-toolbox @nomicfoundation/hardhat-chai-matchers
 ```
 </Callout>
+In a Hardhat project, the default folders are supposed to be for:
+
+- `contracts/` is where the source files for your contracts should be.
+- `scripts/` is where simple automation scripts go.
+- `test/` is where your tests should go.
 
-We delete some files so we start fresh:
+We want to delete some of the default files so we start fresh, e.g. we will create our own .sol file for our contract, etc:
 
 ```bash
 rm contracts/*.sol
 rm scripts/*.js
 rm test/*.js
 ```
 
-In a Hardhat project, the default folders are supposed to be for:
 
-- `contracts/` is where the source files for your contracts should be.
-- `scripts/` is where simple automation scripts go.
-- `test/` is where your tests should go.
-
-We now need to add our last dependency (OpenZeppelin contracts):
+We now need to add our last dependency. The OpenZeppelin contracts:
 
 ```bash
 npm install @openzeppelin/contracts
@@ -135,7 +136,7 @@ Fire up your code editor and let’s start hacking. I’m using VSCode, so I run
 `code .` in my terminal.
 
 Let’s create an empty file named `TierNFT.sol` inside the `contracts/` folder
-and copy this code inside:
+and following the contract and file naming convention, create a contract of the same name:
 
 ```solidity
 // SPDX-License-Identifier: MIT
@@ -145,19 +146,18 @@ contract TierNFT {
 }
 ```
 
-Now that we have our License, the version of solidity we are using and the
+Now that we have our license, the version of Solidity we are using and the
 contract set up, we can add the logic and the variables we need to store.
 
-## What do we need?
+## What do we need? 
+### we sort of need this 'intro' at the start of the lesson......
 
 As we are creating tiers for the categories of our NFTs, we need to also store
-information about tiers in our contracts.
-
-We'll write our smart contract step by step in four stages.
+information about tiers in our contracts. We'll write our smart contract step by step in four stages.
 
 ### Inheriting OpenZeppelin ERC721 and adding a Mint Function
 
-Let’s get started with a simple contract, inheriting OpenZeppelin ERC721 like we did last time.
+Let’s get started by inheriting OpenZeppelin's ERC721.sol like we did last time. We add a constructor to our contract, which will mirror the one from ERC721.sol. 
 
 ```solidity
 // SPDX-License-Identifier: MIT
@@ -173,9 +173,8 @@ contract TierNFT is ERC721 {
 }
 ```
 
-We add a constructor to our contract, which will mirror the one inherited from ERC721.sol. If we had no constructor, the compiler would throw errors.
 
-Now let’s go ahead and add a mint function that only uses `_safeMint` **i don't understand 'only uses'....as opposed to what?**'
+Now let’s go ahead and add a mint function which will call `_safeMint` from the inherited contract, and we'll make it `payable`. We'll see why shortly. Can you remember what `++` does to our total supply?
 
 ```solidity
 // SPDX-License-Identifier: MIT
@@ -201,7 +200,7 @@ contract TierNFT is ERC721 {
 
 ### Adding Tiers and Using Them in the Mint Function
 
-Now add the tiers and assign their values, where each one represents a service subscription.
+Now to make our code neat and easily readable, just before the contract declaration, add the tiers, and assign their values, where each one represents a service subscription. Note that we assign the `constant` keyword, which is what it sounds like - the values won't change, which in turn cuts down a lot on gas costs. Always good to know, but we'll go into 'gas optimisation' for you in a future lesson.
 
 ```solidity
 // SPDX-License-Identifier: MIT
@@ -234,9 +233,9 @@ contract TierNFT is ERC721 {
 }
 ````
 
-We have added `Basic`, `Medium` and `Premium` as tiers and assigned their values. We store what tier each NFT holds in `mapping(uint256 => uint256) public tokenTier;`.
+We have added `Basic`, `Medium` and `Premium` as tiers and assigned their values. We store which tier each NFT holds in `mapping(uint256 => uint256) public tokenTier;`. Mappings are widely used in Solidity, having many advantages. For example, they are a great way to store batches of data and access them efficiently and therefore cheaply through 'key: value' pairs.
 
-Now we need to modify the mint function for the tier NFTs:
+Now we need to modify the mint function with logic to be able to actually access the three tiers of the NFTs separately. We use a 'conditional' `if/else if` statement to achieve this. If you know Javascript, you know `if`, and you know `else`!
 
 ```solidity
     // constructor part of the code...