Fix links to ontology-architecture.pdf

Link to the resource as it is on the official OP-TED GitHub repository
(which is already the one listed under references).

Resolves internal feedback issue PRJ-13.

docs/modules/ROOT/pages/index.adoc

@@ -8,7 +8,7 @@
 :docinfo: shared
 
 
-The https://github.com/OP-TED/model2owl/[*model2owl*] project comprises a set of tools for transforming an UML (v2.5) model from its XMI (v2.5.1) serialisation into a formal OWL ontology, and a SHACL shape. This approach is conformant to the https://semiceu.github.io/style-guide/1.0.0/index.html[SEMIC Style Guide] and with https://github.com/meaningfy-ws/model2owl/blob/master/doc/ontology-architecture/ontology-architecture.pdf[eProcurement Ontology Architecture specification].
+The https://github.com/OP-TED/model2owl/[*model2owl*] project comprises a set of tools for transforming an UML (v2.5) model from its XMI (v2.5.1) serialisation into a formal OWL ontology, and a SHACL shape. This approach is conformant to the https://semiceu.github.io/style-guide/1.0.0/index.html[SEMIC Style Guide] and with https://github.com/OP-TED/model2owl/blob/master/docs/ontology-architecture/ontology-architecture.pdf[eProcurement Ontology Architecture specification].
 
 The UML transformation is performed using XSLT stylesheets under the assumption that the UML model conforms to the set of conventions outlined in the https://meaningfy-ws.github.io/model2owl-docs/public-review/uml/conceptual-model-conventions.html[EPO UML conventions specification]. This set of UML conventions is aligned with and extends the UML conventions specified in https://semiceu.github.io/style-guide/1.0.0/index.html[SEMIC Style Guide].
 
@@ -29,5 +29,5 @@ This documentation is evolving and aims at covering the important aspects that o
 
 This work is developed in the context of https://github.com/eprocurementontology/eprocurementontology[eProcurement ontology project] financed by the Digital Europe Programme and led by the https://op.europa.eu/en/[Publications Office of the European Union].
 
-The tools can be used on any other ontology that is built according to the provided https://github.com/meaningfy-ws/model2owl/blob/master/doc/ontology-architecture/ontology-architecture.pdf[modelling architecture] and xref:uml/conceptual-model-conventions.adoc[UML conceptual model conventions].
+The tools can be used on any other ontology that is built according to the provided https://github.com/OP-TED/model2owl/blob/master/docs/ontology-architecture/ontology-architecture.pdf[modelling architecture] and xref:uml/conceptual-model-conventions.adoc[UML conceptual model conventions].
 

docs/modules/ROOT/pages/references.adoc

@@ -89,7 +89,7 @@ Kunze, John, and Thomas Baker. 2007. “The Dublin Core Metadata Element Set.”
 
 - *[[[ref:semic-style-guide]]semic-style-guide]* SEMIC Style guide v1.0.0, 2023, https://semiceu.github.io/style-guide/1.0.0/index.html
 
-- *[[[ref:epo-arch]]epo-arch]* Costetchi, E. (2020). EProcurement ontology architecture and formalisation specifications. Recommendation, Publications Office of the European Union. Available at: https://github.com/OP-TED/model2owl/blob/master/doc/ontology-architecture/ontology-architecture.pdf
+- *[[[ref:epo-arch]]epo-arch]* Costetchi, E. (2020). EProcurement ontology architecture and formalisation specifications. Recommendation, Publications Office of the European Union. Available at: https://github.com/OP-TED/model2owl/blob/master/docs/ontology-architecture/ontology-architecture.pdf
 
 - *[[[ref:oslo-rules]]oslo-rules]* Thijs, G. (2019) OSLO MODELLERINGSREGELS. Available at: https://github.com/Informatievlaanderen/OSLO-handleiding/blob/master/Modellering/OSLO-Modelleringsregels.pdf