update v2 toc

Signed-off-by: Alex Chi Z <iskyzh@gmail.com>

mini-lsm-book-wip/src/SUMMARY.md

@@ -3,35 +3,43 @@
 [Overview](./00-overview.md)
 [Get Started](./00-get-started.md)
 
----
+# Week 1: Mini-LSM
 
-# Week 1: Storage Format
-
-- [Blocks](./01-block.md)
-- [Sorted String Table (SST)](./02-sst.md)
-- [Merge Iterators](./03-memtable.md)
-- [Storage Engine](./04-engine.md)
+- [Overview](./week1-overview.md)
+  - [Blocks](./week1-01-block.md)
+  - [Sorted String Table (SST)](./week1-02-sst.md)
+  - [Memtables](./week1-03-memtable.md)
+  - [Merge Iterators](./week1-04-merge-iterator.md)
+  - [Read Path](./week1-05-read-path.md)
+  - [Write Path](./week1-06-write-path.md)
 
 # Week 2: Compaction and Persistence
 
-- [Compaction Task](./05-compaction.md)
-- [Compaction Strategy](./06-compaction-strategy.md)
-- [Write-Ahead Log (WAL) and Manifest](./07-recovery.md)
-- [Bloom Filter](./08-bloom-filter.md)
-- [Key Compression](./09-key-compression.md)
+- [Overview](./week2-overview.md)
+  - [Simple Compaction](./week2-01-compaction.md)
+  - [Tiered Compaction](./week2-02-tiered.md)
+  - [Leveled Compaction](./week2-03-leveled.md)
+  - [Manifest](./week2-04-manifest.md)
+  - [Write-Ahead Log (WAL)](./week2-05-wal.md)
+  - [SST Optimizations](./week2-06-sst-optimizations.md)
 
 # Week 3: MVCC
 
-- [Encode the Timestamp](./10-ts.md)
-- [Prefix Bloom Filter](./11-prefix-bloom-filter.md)
-- [Read with Timestamp](./12-mvcc-read.md)
-- [Snapshots and Watermark](./13-watermark.md)
-- [Garbage Collection](./14-garbage-collection.md)
+- [Overview](./week3-overview.md)
 
-# The Rest of Your Life
+# The Rest of Your Life (TBD)
 
-- [I/O Optimization](./15-io-optimization.md)
-- [Block Compression](./16-compression.md)
-- [Async Engine](./17-async.md)
-- [Serializable Snapshot Isolation](./18-serializable.md)
-- [SQL over Mini LSM](./19-sql.md)
+---
+
+# Mini-LSM v1
+
+- [Overview](./00-v1.md)
+  - [Store key-value pairs in little blocks](./01-block.md)
+  - [And make them into an SST](./02-sst.md)
+  - [Now it's time to merge everything](./03-memtable.md)
+  - [The engine is on fire](./04-engine.md)
+  - [Let's do something in the background](./05-compaction.md)
+  - [Be careful when the system crashes](./06-recovery.md)
+  - [A good bloom filter makes life easier](./07-bloom-filter.md)
+  - [Save some space, hopefully](./08-key-compression.md)
+  - [What's next](./09-whats-next.md)