docs: expand anchor and checkpoints page

docs/architecture/anchors.md

@@ -2,7 +2,21 @@
 
 There are a few versions of anchors, but they all have in common that they implement the trait `bdk_chain::Anchor`. For users of `bdk::Wallet`, the most important of these anchors is `bdk_chain::ConfirmationTimeHeightAnchor`.
 
-A `TxGraph` is generic in its Anchor type. 
+You can think of an anchor as the glue that binds a transaction to a block. If a transaction is anchored in a block that is in the best chain, this transaction must therefore also be in the best chain. If that "anchor block" ever gets reorged and the transaction does not have any other anchors, the transaction becomes unconfirmed (since it's not tied to any particular block anymore!). A Transaction can have multiple anchors.
 
-You can think of an anchor as the glue that binds a transaction to a block. If a transaction is anchored in a block that is in the best chain, this transaction is therefore also in the best chain. If that block ever gets reorged, the transaction becomes unconfirmed. A Transaction can have multiple anchors. 
+Every Anchor implementation contains a `BlockId` parameter, and must implement the `Ord` trait, meaning that any two anchors can always be compared and ordered relative to each other, facilitating sorting based on their `BlockId` values.
 
+## ConfirmationTimeHeightAnchor
+
+```rust
+pub struct ConfirmationTimeHeightAnchor {
+    /// The anchor block.
+    pub anchor_block: BlockId,
+    /// The confirmation height of the chain data being anchored.
+    pub confirmation_height: u32,
+    /// The confirmation time of the chain data being anchored.
+    pub confirmation_time: u64,
+}
+```
+
+A `TxGraph` is generic in its `Anchor` type.

docs/architecture/checkpoint.md

@@ -1,6 +1,87 @@
 # CheckPoints
 
-A `CheckPoint` is a type that contains a block height and hash, and potentially a pointer to a previous `CheckPoint`. For example, printing the CheckPoint for the genesis block of testnet, you get this:
-```shell
-CheckPoint(CPInner { block: BlockId { height: 0, hash: 0x000000000933ea01ad0ee984209779baaec3ced90fa3f408719526f8d77f4943 }, prev: None })
+A `CheckPoint` is a type that contains a `BlockId` (height and hash), and potentially a pointer to a previous `CheckPoint`. For example, printing the CheckPoint for the genesis block of testnet, you get this:
+
+```rust
+CheckPoint(
+    CPInner { 
+        block: BlockId {
+            height: 0,
+            hash: 0x000000000933ea01ad0ee984209779baaec3ced90fa3f408719526f8d77f4943
+        },
+        prev: None 
+    }
+)
+```
+
+You can see an example of how checkpoints chain into each other by building a `LocalChain` and printing the `tip` field, which contains its recentmost checkpoint (which in turns points to a previous checkpoint, all the way down to genesis) like so:
+
+```rust
+let local_chain = LocalChain::from_blocks(
+    [
+        (0, Hash::hash("zero".as_bytes())),
+        (1, Hash::hash("first".as_bytes())),
+        (2, Hash::hash("second".as_bytes())),
+        (3, Hash::hash("third".as_bytes())),
+        (12, Hash::hash("twelve".as_bytes())),
+        (17, Hash::hash("seventeen".as_bytes())),
+    ]
+    .into_iter()
+    .collect::<BTreeMap<u32, BlockHash>>(),
+).unwrap();
+
+println!("Local chain checkpoints: \n{:#?}\n", local_chain.tip());
 ```
+
+Which will print:
+```rust
+CheckPoint(
+    CPInner {
+        block: BlockId {
+            height: 17,
+            hash: 0x8a0ca06e16959dd0d1e814fe3b1b2df6e1e01b7f8a8254d6501f765d7abca794,
+        },
+        prev: Some(
+            CPInner {
+                block: BlockId {
+                    height: 12,
+                    hash: 0x91a825c5c1eea6886cda4e98dac99d915697c362e19a2920d5a242e9b4fc5922,
+                },
+                prev: Some(
+                    CPInner {
+                        block: BlockId {
+                            height: 3,
+                            hash: 0xb3803c0a544bad22bd52594014848a1dbf1a6308b69a4dbbb00306f9d9f3cb96,
+                        },
+                        prev: Some(
+                            CPInner {
+                                block: BlockId {
+                                    height: 2,
+                                    hash: 0x928411406d12ade8e2d0dfeb43f2d165923595cb68d89561c2ae7fc6b935840b,
+                                },
+                                prev: Some(
+                                    CPInner {
+                                        block: BlockId {
+                                            height: 1,
+                                            hash: 0xcf0b7afa0779ec616649ecada0e3711b2acee4e5631289ef615b167cb0ac9f4b,
+                                        },
+                                        prev: Some(
+                                            CPInner {
+                                                block: BlockId {
+                                                    height: 0,
+                                                    hash: 0x2cf2de24e85d6179e06f842e74accef3bfa8a3fe0e194fafa30045c9a9187c92,
+                                                },
+                                                prev: None,
+                                            },
+                                        ),
+                                    },
+                                ),
+                            },
+                        ),
+                    },
+                ),
+            },
+        ),
+    },
+)
+```

docs/getting-started/getting-started.md

@@ -26,16 +26,16 @@ cd my_bdk_app
 2. Add `bdk` to your `Cargo.toml` file. Find the latest `bdk@1` release on [`crates.io`](https://crates.io/crates/bdk/versions), for example:
 
 ```shell
-cargo add bdk@1.0.0-alpha.3
+cargo add bdk@1.0.0-alpha.4
 ```
 
 3. Add other required dependencies:
 
 ```shell
-cargo add bdk_esplora@0.7.0
-cargo add bdk_file_store@0.3.0
+cargo add bdk_esplora@0.6.0
+cargo add bdk_file_store@0.4.0
 ```
 
-See the [Wallet with Electrum](./book/electrum-wallet.md) page for how to create and sync a wallet.
+See the [Wallet with Electrum Example](../book/electrum-wallet.md) page for how to create and sync a wallet.
 
 [Getting Started]: https://www.rust-lang.org/learn/get-started