Remove double-broadcasting, move examples/ to tests, refactoring

API:
* Removed automatic "double broadcasting" from cross-track distance; users can do it themselves now.

Docs:
* Moved examples/ into the test suite for now.
* Updated developer instructions in Readme.

Refactoring:
* Refactored usage of _validate() and _promote_shape().
* Used internal helper functions in more places instead of "raw" Numpy funcs.
* Removed unnecessary keepdims=True usage in normalize().
* Improved normalize() performance with in-place operations, and optional inplace= kwarg.
  (TODO: convert to Numpy convention out= instead).
* Improved type hints.
* Renamed _dot_1d() to _dot_1d_scalar() and replaced np.dot() with less-ambiguous np.inner().

Dev:
* Added more Hatch helper scripts.
* Added an IPython startup script with hot reloading.

README.adoc

@@ -26,6 +26,7 @@ library.
 This is also useful for SQL-like database/query engines that support
 batched/vectorized Python UDFs, such as PySpark, DuckDB, and Snowflake.
 
+
 == Installation
 
 I will set up PyPI publishing and a stable versioning scheme eventually.
@@ -36,31 +37,41 @@ For now, install https://pip.pypa.io/en/stable/topics/vcs-support/#git[directly
 pip install git+https://github.com/gwerbin/nvector-lite
 ----
 
+
+== Usage
+
+=== Examples
+
+Refer to the test suite, especially any test called `+test_example+`.
+
+
 == Development
 
 Development requires https://hatch.pypa.io/[Hatch].
 
-First, clone the Git repository.
+Then, just clone the Git repository. Hatch will automatically set up the project environment
+when you run a command for the first time.
 
-Then, set up our Hatch environments:
+Run tests:
 
 [,shell]
 ----
-hatch python install all
-hatch env create dev
+hatch run dev:pytest
 ----
 
-Technically this is optional and will be done automatically by `+hatch run+`.
-But it's nice to have everything set up and ready to avoid a long wait for the
-first command.
-
-Run tests:
+Run an interactive Python console with hot-reloading enabled:
 
 [,shell]
 ----
-hatch run dev:pytest
+hatch run dev:repl
 ----
 
-== Examples
+Run any other command (e.g. Python) in the dev environment:
 
-See `+examples/+`
+[,shell]
+----
+hatch run dev:python ...
+hatch run dev:python -m pdb ...
+hatch run dev:/bin/sh ...
+watch -n 60 hatch run dev:pytest -k test_example
+----

ipython_startup.py

@@ -0,0 +1,6 @@
+from IPython import get_ipython
+
+ipython = get_ipython()
+ipython.run_line_magic("reload_ext",  "autoreload")
+ipython.run_line_magic("aimport", "nvector_lite")
+ipython.run_line_magic("autoreload", "2")