docs: add data source docs and contribution guide

Author: zhangyu94

CONTRIBUTING.md

@@ -36,6 +36,14 @@ libquery_extensions/    - the Python package
 
 Use [Black](https://github.com/psf/black) to detect code style issues and fix the issues before committing.
 
+## Publishing the Package
+
+The steps to publish the package:
+
+1. Bump the version in `pyproject.toml`.
+2. create a new tag for the version with `git tag v*.*.*`.
+3. push the tag to Github with `git push origin v*.*.*`, which will trigger the Github workflow at `.github/workflow/publish-to-pypi.yml` to automatically publish the package to PyPI.
+
 ## Thanks
 
 Thank you again for being interested in this project! You are awesome!

libquery_extensions/alabama_maps/README.md

@@ -0,0 +1,16 @@
+# Alabama Maps
+
+**URL:** <http://alabamamaps.ua.edu/historicalmaps/>
+
+**Contributor:**
+- Collector: [Cartographic Research Laboratory](http://alabamamaps.ua.edu/cartlab/index.html) at the University of Alabama ([reference](http://alabamamaps.ua.edu/about.html))
+- Original Data Sources: this [link](http://alabamamaps.ua.edu/historicalmaps/about.html) describes the source of 69285 maps
+
+**Data Source Size:** 77309 maps + 53869 aerial photos ([reference](http://alabamamaps.ua.edu/index.html)) (last accessed on 2023/10/19)
+
+**Term of Use:**
+>  The Historical Map Archive is a digitized collection of selected map holdings from the University of Alabama Map Library, the W. S. Hoole Special Collections Library, the Rucker Agee Collection of the [Birmingham Public Library](http://www.bham.lib.al.us/), the [Geological Survey of Alabama](http://www.gsa.state.al.us/), and the [Alabama Department of Archives and History](https://www.archives.state.al.us/). We are indebted to these organizations for their cooperation in facilitating the introduction of these digital maps to the Internet. Maps located in the Historical Map Archive may be used in publication only if permission is given by the map owner. This information can be found under the heading "Original Source" in the information for each map. Interested parties may contact us at alabama.maps@ua.edu, and we will be happy to provide the owner's contact information. ([Source](http://alabamamaps.ua.edu/about.html))
+
+**Last Update:** 2022/05/25 ([reference](http://alabamamaps.ua.edu/index.html))
+
+**Search Function:** [link](http://alabamamaps.ua.edu/searchengine.htm)

libquery_extensions/alabama_maps/_fetch_metadata.py

@@ -1,5 +1,11 @@
 """
 Utility functions for getting metadata from Alabama Maps.
+
+Implementation Notes
+--------------------
+1. Alabama Maps website does not provide search function.
+Thus, the user needs to manually gather the URLs of pages
+to be processed by operating in the navigation page.
 """
 
 import os
@@ -53,11 +59,12 @@ def _parse_download_url(view_url: str, driver: webdriver.Chrome) -> str:
     parse_result = parse.urlparse(download_url)
     query = parse.parse_qs(parse_result.query)
 
-    # Decides the resolution of the returned image
+    # Get a high-resolution image download URL:
+    # - Set the resolution of the returned image.
     query["lev"] = 0
-    # Decides the width of the returned image
+    # - Set the width of the returned image.
     query["wid"] = 5000
-    # Decides the height of the returned image
+    # - Set the height of the returned image.
     query["hei"] = 4000
 
     del query["props"]

libquery_extensions/british_library/collection_items/README.md

@@ -0,0 +1,3 @@
+# British Library Collection Items
+
+**URL:** <https://www.bl.uk/collection-items?page=1>

libquery_extensions/british_library/images_online/README.md

@@ -0,0 +1,6 @@
+# British Library Images Online
+
+**URL:** <https://imagesonline.bl.uk>
+
+**Term of Use:**
+> Please note that all images on Images Online except for those in Copyright are available to download as JPEGs free of charge at dimensions of 2000px (long-side) at 300 PPI. This is sufficient quality to print up to A5. Please use the Free Download option in the drop-down menu when selecting images. Any image(s) downloaded this way are free to use without restriction. The images are not made available as Public Domain, and will need to be credited © British Library Board (including the shelfmark, folio/page number) when used. ([Source](https://imagesonline.bl.uk/))

libquery_extensions/telefact/README.md

@@ -0,0 +1,16 @@
+# Telefact: 1938-1945 by Pictograph Corporation
+
+**URL:** <https://modley-telefact-1939-1945.tumblr.com>
+
+**Contributor:**
+- [Jason Forrest](https://www.jasonforrestftw.com/) (collector)
+- [Rudolf Modley](https://en.wikipedia.org/wiki/Rudolf_Modley) (creator)
+
+**Data Source Content:**
+> Telefact was a syndicated series of isotypes by the Pictograph Corporation. Rudolf Modley (1906 - 1976) was an Austrian-American research executive, graphic designer, management consultant and author, who founded Pictorial Statistics Inc. in 1934. He illustrated and wrote a series of books on pictorial statistics and pictorial symbolism. Modley is known for introducing and populizing the Isotype picture language in the United States, whereby he developed an own version of pictorial statistics. He also designed many pictorial symbols in the 1930s and 1940s, and worked on standardization of pictorial symbols. These images were found in various newspapers, digitized, and edited by Jason Forrest in April 2020. For more: https://www.jasonforrestftw.com. ([Source](https://modley-telefact-1939-1945.tumblr.com/) last accessed on 2023/10/19)
+
+**Data Source Size:** 264 (as of 2022/06/26)
+
+**Term of Use:** Unknown
+
+**Related Blog:** <https://medium.com/nightingale/the-telefacts-of-life-rudolf-modleys-isotypes-in-american-newspapers-1938-1945-d5478faa5647>