fix tutorial URL

BUILDING.md

@@ -0,0 +1,35 @@
+# Building Cozo from source
+
+You need to install the [Rust toolchain](https://www.rust-lang.org/tools/install) on your system.
+You also need a C++17 compiler.
+
+Clone the Cozo git repo:
+
+```bash
+git clone https://github.com/cozodb/cozo.git --recursive
+```
+
+You need to pass the `--recursive` flag so that submodules are also cloned. 
+Next, run in the root of the cloned repo:
+
+```bash
+cargo build --release
+```
+
+Wait for potentially a long time, and you will find the compiled binary in `target/release`.
+
+You can run `cargo build --release -F jemalloc` instead
+to indicate that you want to compile and use jemalloc as the memory allocator for the RocksDB storage backend,
+which can make a difference in performance depending on your workload.
+
+To build the C library:
+
+```bash
+cargo build --release --manifest-path=cozo-lib-c/Cargo.toml
+```
+
+To build the Java library used by [cozo-lib-java](https://github.com/cozodb/cozo-lib-java):
+
+```bash
+cargo build --release --manifest-path=cozo-lib-java/Cargo.toml
+```

README.md

@@ -296,7 +296,7 @@ you will be greeted with a very simple JS client:
 
 Now you know how to run queries in your chosen language, you can start learning CozoScript:
 
-* Start with the [Tutorial](https://nbviewer.org/github/cozodb/cozo/blob/main/docs/tutorial/tutorial.ipynb) to learn the
+* Start with the [Tutorial](https://nbviewer.org/github/cozodb/cozo-docs/blob/main/tutorial/tutorial.ipynb) to learn the
   basics;
 * Continue with the [Manual](https://cozodb.github.io/current/manual/) for the fine points.
 
@@ -340,7 +340,7 @@ in specific situations:
       performance problems easier.
 * Your data may be simple, even a single table, but it is inherently a graph.
     * We have seen an example in
-      the [Tutorial](https://nbviewer.org/github/cozodb/cozo/blob/main/docs/tutorial/tutorial.ipynb):
+      the [Tutorial](https://nbviewer.org/github/cozodb/cozo-docs/blob/main/tutorial/tutorial.ipynb):
       the air route dataset, where the key relation contains the routes connecting airports.
     * In traditional databases, when you are given a new relation,
       you try to understand it by running aggregations on it to collect statistics: