Merge pull request #262 from Exabyte-io/docs/SOF-7063

SOF-7063: new documentation on DFT+U and Hubbard parameter calculation

Author: pranabdas

.gitmodules

@@ -1,3 +1,3 @@
 [submodule "esse"]
 	path = data/esse
-	url = https://github.com/Exabyte-io/exabyte-esse.git
+	url = https://github.com/Exabyte-io/esse.git

README.md

@@ -106,7 +106,7 @@ Leave more than one empty line (2-3) when "coming back" to higher-level header f
 
 #### Admonition Styles
 
-There are multiple [admonition](https://squidfunk.github.io/mkdocs-material/extensions/admonition/) classes available in MKDocs: tip (green), warning (orange), error (red), note (blue), and many others. To insert them in documentation pages, enter them with the following style:
+There are multiple [admonition](https://squidfunk.github.io/mkdocs-material/reference/admonitions/) classes available in MKDocs: tip (green), warning (orange), error (red), note (blue), and many others. To insert them in documentation pages, enter them with the following style:
 
 ```text
 !!!tip "Unused credits"