README.rst: Add a "development" installation section

Also cleanup a bit on requirements and installation guide.

Signed-off-by: Aaron LI <aly@aaronly.me>

1 files changed, 12 insertions, 2 deletions

diff --git a/README.rst b/README.rst
index 7c658dd..e4bf1c1 100644
--- a/README.rst
+++ b/README.rst
@@ -59,7 +59,7 @@ Requirements
 * `CFITSIO <https://heasarc.gsfc.nasa.gov/fitsio/fitsio.html>`_
 * `HEALPix <http://healpix.sourceforge.net/>`_:
   only the C++ library required by `healpy <https://github.com/healpy/healpy>`_.
-* `LLVM <http://llvm.org/>`_: = 3.8
+* `LLVM <http://llvm.org/>`_:
   (required by `llvmlite <http://llvmlite.pydata.org/>`_ which is a
   dependency of `Numba <http://numba.pydata.org/>`_)
 
@@ -70,7 +70,7 @@ Installation
 
    $ git clone https://github.com/liweitianux/fg21sim
 
-2. Install the above system requirements: CFITSIO, HEALPix, and LLVM.
+2. Install the above required software and libraries.
 
 3. Install the required third-party Python packages.
    And it is recommended to use the `virtual environment`_::
@@ -92,6 +92,16 @@ Installation
    $ fg21sim-webui --help
 
 
+Development
+-----------
+To ease development and tests, you may want to install this package in
+an **editable state**, instead of using the *virtual environment*::
+
+    $ cd fg21sim/
+    $ pip3 install --user -r requirements.txt
+    $ pip3 install --editable .
+
+
 Documentations
 --------------
 To get started, read the `User Guide`_.