Add citation and update readme for topology-preserving line densification paper

[nihalzp]

Additionally, this PR fixes the wrong DOI for the 2018 paper. Initially, it pointed to the older 2004 diffusion paper.

Closes

• Add Suggested Citation in .cff Format #311

[Copilot]

Pull request overview

Updates the repository’s citation guidance to reference the new topology-preserving line densification paper and corrects the previously incorrect DOI for the 2018 PNAS flow-based cartogram paper, aligning with Issue #311’s request to add a .cff citation file.

Changes:

• Update README.md to cite the 2026 topology-preserving line densification paper and fix the 2018 PNAS paper DOI.
• Add CITATION.cff with a preferred-citation pointing to the 2026 paper.
• Adjust docs CI support files (.markdown-link-check.json, .cspell.json) to accommodate the updated README content.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
README.md	Updates primary citation to the 2026 paper and corrects the 2018 DOI (but currently contains a license inconsistency).
CITATION.cff	Adds a Citation File Format entry with preferred citation for the 2026 paper.
.markdown-link-check.json	Ignores new README links that may fail automated link checking.
.cspell.json	Adds new domain-specific/proper-noun words introduced by the README update.

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[github-actions]

🚦 Performance Comparison ^{(α=0.05, ±5%)}

🗺️ Total maps

34

❌ Failed

0

🚀 Speed-ups

2

🐢 Slow-downs

0

⚖️ No change

32

---

❌ Failures

None 😎

🚀 Speed-ups (2)

map	main	pr	Δ %	p
contiguous_​usa_​by_​county_​since_​2001/​usa_​population_​by_​county_​2021.csv	35.364±2.992	26.890±5.771	-24.0	0.014
world_​by_​region/​world_​population_​by_​region.csv	8.167±0.049	7.240±0.670	-11.4	0.019

🐢 Slow-downs (0)

none

⚖️ No significant change (32)

map	main	pr	Δ %	p
algeria_​by_​wilaya_​since_​2019/​algeria_​population_​by_​wilaya_​2022.csv	0.722±0.004	0.701±0.006	-2.9	0.000
australia_​by_​state_​and_​territory_​since_​1942/​australia_​population_​by_​state_​and_​territory_​2021.csv	0.750±0.009	0.728±0.003	-2.8	0.001
austria_​by_​state_​since_​1945/​austria_​population_​by_​state_​2020.csv	0.223±0.001	0.219±0.002	-1.7	0.004
bahamas_​by_​district_​since_​1999/​bahamas_​population_​by_​district_​2010.csv	3.581±0.050	3.504±0.020	-2.1	0.011
belgium_​by_​region_​simplified_​since_​1995/​belgium_​population_​by_​region_​simplified_​2022.csv	0.068±0.001	0.068±0.001	-0.4	0.564
belgium_​by_​region_​since_​1995/​belgium_​population_​by_​region_​2022.csv	0.092±0.001	0.091±0.001	-0.6	0.351
brazil_​by_​state_​since_​1988/​brazil_​population_​by_​state_​2021.csv	0.642±0.010	0.625±0.004	-2.8	0.005
china_​by_​province_​with_​chinese_​taipei_​since_​1998/​china_​population_​by_​province_​2020.csv	0.796±0.012	0.780±0.016	-2.1	0.076
conterminous_​usa_​by_​state_​since_​1959/​conterminous_​usa_​population_​by_​state_​2020.csv	0.452±0.003	0.435±0.001	-3.8	0.000
croatia_​by_​county_​since_​1992/​croatia_​covid_​cases_​by_​county_​2022.csv	0.210±0.001	0.205±0.001	-2.3	0.000
croatia_​by_​county_​since_​1992/​croatia_​population_​by_​county_​2021.csv	0.211±0.003	0.203±0.001	-3.4	0.001
egypt_​by_​governorate_​since_​2009/​egypt_​population_​by_​governate_​2017.csv	0.795±0.000	0.776±0.004	-2.3	0.000
england_​by_​region_​since_​2023/​england_​population_​by_​region_​2022.csv	1.311±0.024	1.271±0.021	-3.1	0.013
eu_​by_​country_​until_​2020/​eu_​population_​by_​country_​2021.csv	1.722±0.027	1.662±0.011	-3.5	0.002
eu_​by_​region_​until_​2020/​eu_​population_​by_​region_​2020.csv	4.961±0.034	4.883±0.055	-1.6	0.017
france_​by_​metropolitan_​region_​since_​2016/​france_​population_​by_​metropolitan_​region_​2008.csv	0.251±0.002	0.244±0.002	-2.9	0.000
germany_​by_​state_​since_​1990/​germany_​population_​by_​state_​2011.csv	0.151±0.001	0.148±0.001	-2.1	0.000
indonesia_​by_​province_​since_​2022/​indonesia_​population_​by_​province_​2024.csv	0.359±0.002	0.347±0.001	-3.2	0.000
japan_​by_​prefecture_​since_​1888/​japan_​population_​by_​prefecture_​2020.csv	0.697±0.012	0.677±0.015	-2.8	0.031
malaysia_​by_​state_​since_​2001/​malaysia_​population_​by_​state_​2020.csv	0.350±0.004	0.337±0.001	-4.0	0.000
malaysia_​by_​state_​since_​2001/​malaysia_​population_​by_​state_​2020_​insetted.csv	0.306±0.002	0.301±0.005	-1.9	0.030
metropolitan_​france_​by_​departement_​since_​2015/​metropolitan_​france_​population_​by_​departement_​2022.csv	0.991±0.011	0.963±0.009	-2.9	0.001
russia_​by_​federal_​subject_​since_​2008/​russia_​population_​by_​federal_​subject_​2010.csv	1.334±0.008	1.332±0.005	-0.1	0.685
singapore_​by_​planning_​area_​since_​1999/​singapore_​population_​by_​planning_​area_​2015.csv	2.295±0.014	2.231±0.004	-2.8	0.000
switzerland_​by_​canton_​since_​1999/​switzerland_​gdp_​in_​billion_​chf_​by_​canton_​2019.csv	0.360±0.003	0.352±0.010	-2.2	0.108
switzerland_​by_​canton_​since_​1999/​switzerland_​population_​by_​canton_​2016.csv	0.312±0.003	0.306±0.007	-1.9	0.088
tunisia_​by_​governorate_​since_​1994/​tunisia_​population_​by_​governate_​2014.csv	0.337±0.002	0.327±0.001	-2.9	0.000
usa_​by_​state_​since_​1959/​usa_​population_​by_​state_​2020.csv	0.719±0.020	0.738±0.009	+2.6	0.080
usa_​by_​state_​since_​1959/​usa_​population_​by_​state_​2020_​insetted.csv	0.531±0.002	0.514±0.001	-3.2	0.000
vietnam_​by_​province_​since_​1996/​vietnam_​population_​by_​province_​2019.csv	0.669±0.002	0.649±0.004	-3.0	0.000
world_​by_​country_​since_​2022/​world_​population_​by_​country_​2010.csv	6.711±0.013	6.605±0.031	-1.6	0.000
world_​by_​region_​wo_​antarctica/​world_​population_​by_​region_​wo_​antarctica.csv	7.953±0.076	7.680±0.045	-3.4	0.000