Update README with COLING 2025 paper and missing references

Add the primary COLING 2025 publication with BibTeX citation,
the Greeklish-to-Greek (LREC-COLING 2024) reference, and
improve formatting with proper markdown links and bold labels.

README.md

@@ -4,19 +4,61 @@ language:
 - el
 pipeline_tag: token-classification
 ---
-This repository contains the models used in the gr-nlp-toolkit project (https://github.com/nlpaueb/gr-nlp-toolkit).
--
+This repository contains the models used in the [gr-nlp-toolkit](https://github.com/nlpaueb/gr-nlp-toolkit) project.
+
 The toolkit includes the following models, all designed specifically for processing the Greek language:
-- Named Entity Recognition (NER): Identifies and classifies named entities in Greek text,
+- **Named Entity Recognition (NER)**: Identifies and classifies named entities in Greek text,
   such as names of people, organizations, and locations.
-- Dependency Parsing (DP): Analyzes the grammatical structure of Greek sentences by identifying relationships between words and their dependencies.
-- Part Of Speech tagging (POS): Tags each word in Greek text with its corresponding part of speech (e.g., noun, verb, adjective), along with its morphological features.
+- **Dependency Parsing (DP)**: Analyzes the grammatical structure of Greek sentences by identifying relationships between words and their dependencies.
+- **Part Of Speech tagging (POS)**: Tags each word in Greek text with its corresponding part of speech (e.g., noun, verb, adjective), along with its morphological features.
 
 **Note:**
   These models cannot be used as standalone tools; they are integrated into the gr-nlp-toolkit and can only be utilized through it.
 
-References:
+## Paper
+
+The software was presented as a paper at **COLING 2025**.
+Read the full technical report/paper here: [https://aclanthology.org/2025.coling-demos.17/](https://aclanthology.org/2025.coling-demos.17/)
+
+If you use our toolkit, please cite it:
+```bibtex
+@inproceedings{loukas-etal-coling2025-greek-nlp-toolkit,
+    title = "{GR}-{NLP}-{TOOLKIT}: An Open-Source {NLP} Toolkit for {M}odern {G}reek",
+    author = "Loukas, Lefteris  and
+      Smyrnioudis, Nikolaos  and
+      Dikonomaki, Chrysa  and
+      Barbakos, Spiros  and
+      Toumazatos, Anastasios  and
+      Koutsikakis, John  and
+      Kyriakakis, Manolis  and
+      Georgiou, Mary  and
+      Vassos, Stavros  and
+      Pavlopoulos, John  and
+      Androutsopoulos, Ion",
+    editor = "Rambow, Owen  and
+      Wanner, Leo  and
+      Apidianaki, Marianna  and
+      Al-Khalifa, Hend  and
+      Eugenio, Barbara Di  and
+      Schockaert, Steven  and
+      Mather, Brodie  and
+      Dras, Mark",
+    booktitle = "Proceedings of the 31st International Conference on Computational Linguistics: System Demonstrations",
+    month = jan,
+    year = "2025",
+    address = "Abu Dhabi, UAE",
+    publisher = "Association for Computational Linguistics",
+    url = "https://aclanthology.org/2025.coling-demos.17/",
+    pages = "174--182",
+}
+```
+
+## References
+
+While many methodology details are shared in the [GR-NLP-TOOLKIT paper publication @ COLING 2025 (see above)](https://aclanthology.org/2025.coling-demos.17/), additional research details can be found here:
+
+1. C. Dikonimaki, "A Transformer-based natural language processing toolkit for Greek -- Part of speech tagging and dependency parsing", BSc thesis, Department of Informatics, Athens University of Economics and Business, 2021. http://nlp.cs.aueb.gr/theses/dikonimaki_bsc_thesis.pdf *(POS/DP/Morphological tagging processor)*
 
-- C. Dikonimaki, "A Transformer-based natural language processing toolkit for Greek -- Part of speech tagging and dependency parsing", BSc thesis, Department of Informatics, Athens University of Economics and Business, 2021. http://nlp.cs.aueb.gr/theses/dikonimaki_bsc_thesis.pdf
+2. N. Smyrnioudis, "A Transformer-based natural language processing toolkit for Greek -- Named entity recognition and multi-task learning", BSc thesis, Department of Informatics, Athens University of Economics and Business, 2021. http://nlp.cs.aueb.gr/theses/smyrnioudis_bsc_thesis.pdf *(NER processor)*
 
-- N. Smyrnioudis, "A Transformer-based natural language processing toolkit for Greek -- Named entity recognition and multi-task learning", BSc thesis, Department of Informatics, Athens University of Economics and Business, 2021. http://nlp.cs.aueb.gr/theses/smyrnioudis_bsc_thesis.pdf
+3. A. Toumazatos, J. Pavlopoulos, I. Androutsopoulos, & S. Vassos, "Still All Greeklish to Me: Greeklish to Greek Transliteration." In Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024) (pp. 15309-15319). https://aclanthology.org/2024.lrec-main.1330/ *(Greeklish-to-Greek processor)*