Update README.md

Hi all,
I changed the order of the README entries here so that the citation is somewhat more obvious (referring to gitter discussion). Feel free to revert this change if undesirable

README.md

@@ -15,6 +15,12 @@ and can be joined [here](https://teams.microsoft.com/l/meetup-join/19%3ameeting_
 3. [Discussion forum](https://github.com/spine-tools/SpineOpt.jl/discussions/categories/support) (support section) can be used when you don't know how to get something done or you don't quite know why something isn't working. It's highly appreciated if other users can contribute by helping each other (developers are short on time).
 4. [Issue tracker](https://github.com/spine-tools/SpineOpt.jl/issues) should be used only when there is a missing feature or something should work but it's not working. Update your tools and test with latest software before submitting an issue. In case of new feature, make sure there is no existing issue. Issues reporting bugs should provide sufficient information to enable locating and fixing the bug.
 
+### Citing SpineOpt
+
+Please cite [this article](https://doi.org/10.1016/j.esr.2022.100902) when referring to SpineOpt in scientific writing.
+
+```Ihlemann, M., Kouveliotis-Lysikatos, I., Huang, J., Dillon, J., O'Dwyer, C., Rasku, T., Marin, M., Poncelet, K., & Kiviluoma, J. (2022). SpineOpt: A flexible open-source energy system modelling framework. Energy Strategy Reviews, 43, [100902]. https://doi.org/10.1016/j.esr.2022.100902```
+
 ### Compatibility
 
 This package requires [Julia](https://julialang.org/) 1.6 or higher.
@@ -255,12 +261,6 @@ See [CONTRIBUTING.md](CONTRIBUTING.md)
 
 SpineOpt is licensed under GNU Lesser General Public License version 3.0 or later.
 
-### Citing SpineOpt
-
-Please cite [this article](https://doi.org/10.1016/j.esr.2022.100902) when referring to SpineOpt in scientific writing.
-
-```Ihlemann, M., Kouveliotis-Lysikatos, I., Huang, J., Dillon, J., O'Dwyer, C., Rasku, T., Marin, M., Poncelet, K., & Kiviluoma, J. (2022). SpineOpt: A flexible open-source energy system modelling framework. Energy Strategy Reviews, 43, [100902]. https://doi.org/10.1016/j.esr.2022.100902```
-
 ### Acknowledgements
 
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