docs: added technical concepts to typographical conventions

Signed-off-by: pasched <[email protected]>

Author: pasched

general_docs/conventions.adoc

@@ -51,9 +51,10 @@ This documentation uses the following typographical conventions:
 |===
 |Mark-up                          |Definition
 |`Code elements`                  |This format is used for code elements, such as technical names of classes and attributes, as well as attribute values.
+| Technical concepts              |This format is used for technical concepts. Technical concepts as opposed to code elements do not have a special highlighting.
 |```[blue]#Code snippets#```      |This format is used for excerpts of code that serve as an example for implementation.
 |_Terms_                          |This format is used to introduce glossary terms, new terms and to emphasize terms.
 |`[green]#Mathematical elements#` |This format is used for calculations and mathematical elements.
 |`[green]#<element>#`             |This describes a tag for an XML element
 |`@attribute`                     |The "@" identifies an attribute of an XML element.
-|===
+|===