feat: PLOS SearchSource

[geritwagner]

Description

Create colrev.plos as a new CoLRev package to interface with the Public Library of Science (PLOS) via its REST API, enabling direct search and retrieval of articles from PLOS.

Implementation Notes

• Use the PLOS REST API to support search operations, drawing inspiration from the colrev.crossref package.
• The packages docs page explains the steps of developing CoLRev packages.
• The search-feed offers functionality for storing records.
• CEP003 describes principles for SearchSources.
• CEP002 describes the standard data schema for records.

User Story

1. The user initializes a CoLRev project using colrev init.
2. He/she conducts a search operation with colrev search -a colrev.plos, specifying search parameters relevant to their topic.
3. The package retrieves records based on the parameters and saves them in the data/search directory of the project.
4. When users run colrev load, the records from the search directory are added to the data/records.bib file, which integrates all search results in the project.
5. When users run colrev search again, records are retrieved from the API, updating the existing records.

Expected Effort

2 months, 3-4 people.