Fixed image issues

Author: DsposalTom

docs/1_Start_Here/1_4_Data_Schema.md

@@ -1,4 +1,6 @@
 # Data Schema
 
-<a href="/img/schema-v1.1-2022-12-20.jpg" target="_blank" title="Open schema in new tab">![Schema](../img/schema-v1.1-2022-12-20.jpg)</a>
-
+<figure markdown>
+![Schema](../img/schema-v1.1-2022-12-20.jpg)
+  <figcaption>Data schema</figcaption>
+</figure>

docs/3_Data_Specification/3_2_Material.md

@@ -2,7 +2,10 @@
 
 Materials should be provided as a separate csv file, in tidy format. This means that each row of the csv file should be one material for a component. An example is provided.
 
-<a href="/img/materials-v1.0-2022-12-20.png" target="_blank"><img src="/img/materials-v1.0-2022-12-20.png"target="_blank" title="Open schema in new tab" width="200px"></img></a>
+<figure markdown>
+![Schema](../img/materials-v1.0-2022-12-20.png){ width="450" }
+  <figcaption>Data schema</figcaption>
+</figure>
 
 The specification of this csv file is as follows: