Update documentation

Author: adriancaruana

README.md

@@ -5,6 +5,8 @@ RefMan - A Simple python-based reference manager
 `RefMan` capitalises on [Sci-hub](https://sci-hub.se/) and [crossref](https://crossref.org) to 
 provide a very simple Python-based reference manager.
 
+The goal of `RefMan` is to prioritise getting bibliographic data and PDFs, wihtout having to worry about databases or manually downloading and maintaining references yourself.
+
 `RefMan` maintains:
  1. a BibTeX bibliography file `ref.bib`, and
  2. a directory of `pdf`'s in a `REFMAN_DATA`.
@@ -14,22 +16,60 @@ path listed under the `REFMAN_DATA` environment variable.
 
 ## How to use `RefMan`
 
-Adding new papers to `refman_data` can be achieved in two ways:
- 1. With a string-separated list of DOIs using `-d, --doi`, or
- 2. With a BibTeX string using `-b, --bibtex`, alongside an optional PDF (url or local-path) using `-p, --pdf`.
+Adding new papers to `refman_data` can be achieved in three ways:
+ 1. With a DOI, using `-d, --doi`, or
+ 2. With an `arxiv` reference using `-a, --arxiv`, or
+ 3. As a last-resort, with a BibTeX string using `-b, --bibtex`, alongside an optional PDF (url or local-path) using `-p, --pdf`.
+
+## Installing
+
+```bash
+git clone https://https://github.com/adriancaruana/refman
+cd refman
+./install
+```
+
+## Getting Started
+
+```bash
+# Make a directory to store references
+mkdir ~/refman_data
+
+# Set the REFMAN_DATA environment variable. Add this to your `.bashrc` for persistence.
+export REFMAN_DATA=$HOME/refman_data
+
+# Add a paper using a DOI:
+refman -d 10.1103/PHYSREVLETT.116.061102
+
+# Add a paper using an `arxiv` reference
+refman -a 2103.16574
+
+# Add a paper using a bibtex string & pdf.
+refman -b "@inproceedings{devlin2018bert,
+	title="BERT: Pre-training of Deep Bidirectional Transformers for Language Understanding",
+	author="Jacob {Devlin} and Ming-Wei {Chang} and Kenton {Lee} and Kristina N. {Toutanova}",
+	booktitle="Proceedings of the 2019 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 1 (Long and Short Papers)",
+	pages="4171--4186",
+	year="2018"
+}" -p "https://www.aclweb.org/anthology/N19-1423.pdf"
+```
+
+## Usage
 
 ```
-usage: refman [-h] [-d DOI [DOI ...]] [-b BIBTEX] [-p PDF]
+usage: refman [-h] [-d DOI] [-a ARXIV] [-b BIBTEX] [-p PDF] [-k KEY]
 
 RefMan - A Simple python-based reference manager.
 
 optional arguments:
   -h, --help            show this help message and exit
-  -d DOI [DOI ...], --doi DOI [DOI ...]
-                        Tries to find and download the paper using the DOI. Append multiple papers using a space-separated list
+  -d DOI, --doi DOI     Tries to find and download the paper using the DOI.
+  -a ARXIV, --arxiv ARXIV
+                        Gets the paper from an Arxiv reference string.
   -b BIBTEX, --bibtex BIBTEX
-                        Adds an entry to the database from a bibtex-string. Optionally, provide -p, --pdf to associate this entry with a
-                        PDF.
-  -p PDF, --pdf PDF     Adds an entry to the database from a bibtex-string. Optionally, provide -p, --pdf to associate this entry with a
-                        PDF.
+                        Adds an entry to the database from a bibtex-string. Optionally, provide -p,
+                        --pdf to associate this entry with a PDF.
+  -p PDF, --pdf PDF     Adds an entry to the database from a bibtex-string. Optionally, provide -p,
+                        --pdf to associate this entry with a PDF.
+  -k KEY, --key KEY     Explicitly define the key to use (without hash) for the paper.
 ```