update instructions for Mac OSX

Makefile

@@ -5,7 +5,9 @@
 .PRECIOUS:
 .SUFFIXES:
 
-SHELL:=/bin/bash -e -o pipefail -O globstar
+
+SHELL:=bash -e -o pipefail -O globstar
+
 SELF:=$(firstword $(MAKEFILE_LIST))
 
 VE_DIR=venv

README.md

@@ -105,10 +105,18 @@ answer](https://apple.stackexchange.com/questions/254380/why-am-i-getting-an-inv
 
 ## Quick Start
 
-On Ubuntu 16.04:
+### OSX
+
+    $ brew install python libpq
+
+### On Ubuntu 16.04
 
     $ sudo apt install -y python3-dev gcc zlib1g-dev tabix
-    (OSX: $ brew install python libpq)
+
+### All platforms
+
+    $ python -m venv venv
+    $ source venv/bin/activate
     $ pip install seqrepo
     $ sudo mkdir -p /usr/local/share/seqrepo
     $ sudo chown $USER /usr/local/share/seqrepo
@@ -157,6 +165,14 @@ a moderate value (>10) will greatly increase performance of sequence retrieval.
 
 ## Developing
 
+### OSX
+
+    brew install python libpq bash
+
+### Ubuntu
+
+    sudo apt install -y python3-dev gcc zlib1g-dev tabix
+
 Here's how to get started developing:
 
     make devready

pyproject.toml

@@ -41,11 +41,12 @@ dev = [
     "pytest-optional-tests",
     "pytest ~= 7.1",
     "pyright~=1.1",
+    "tqdm ~= 4.66",
     "tox ~= 3.25",
     "vcrpy",
 ]
 docs = ["mkdocs"]
-loading = ["tqdm ~= 4.66", "requests_html ~= 0.10"]
+loading = ["requests_html ~= 0.10"]
 
 [project.scripts]
 seqrepo = "biocommons.seqrepo.cli:main"