Clean-up README - remove duplicate contributing guide

Author: dalito

README.md

@@ -17,9 +17,8 @@ It uses the [voc4cat-tool](https://github.com/nfdi4cat/voc4cat-tool) and GitHub
 ## Basic principles
 
 Voc4cat makes contributing easy for everyone with a GitHub account.
-The process is essentially *(see further below for details,
-browse through our [step-by-step guide](https://nfdi4cat.github.io/voc4cat/docs_usage/published-guidelines-v2.html#contribution-step-by-step-guide),
-or read the guide in pdf form with screenshots of each step (https://zenodo.org/records/13757351)*.
+The process is essentially *(browse through our [step-by-step guide](https://nfdi4cat.github.io/voc4cat/docs_usage/how-to-contribute.html),
+or read the guide in pdf form with screenshots of each step (https://zenodo.org/records/13757351)*:
 
 - Download the [most current vocabulary file (xlsx)](https://nfdi4cat.github.io/voc4cat/dev/voc4cat.xlsx),
 - Edit the vocabulary file in Excel,
@@ -78,44 +77,12 @@ Both services offer API access to voc4cat. Skosmos has more SKOS-specific featur
 
 To discuss about the **voc4cat**-vocabulary maintained here, create an [issue](https://github.com/nfdi4cat/voc4cat/issues).
 
-To contribute new concepts or collections or change existing ones, you may either submit your contributions as Excel/xlsx-file or (as an expert) as new/changed turtle file.
+To add new concepts or collections or change existing ones, please follow our [*"How to contribute?"*](https://nfdi4cat.github.io/voc4cat/docs_usage/how-to-contribute.html#) guide.
 
 > Small contributions like adding a single concept are as valuable as bigger ones.
 > In fact if you plan a bigger change (50+ concepts), consider splitting up the additions/changes into smaller chunks
 > with max. ~20 changes to make the review process not too hard for the reviewers and you as author.
 
-Here are the steps for submitting updates via Excel/xlsx:
-
-<details>
-
-- Get the Excel/xlsx-vocabulary file
-  - The most recent version of the vocabulary is always available via GitHub-pages https://nfdi4cat.github.io/voc4cat/dev/voc4cat.xlsx
-- Make changes to the Excel file. If you want to add something new you need to [request a range of IDs](https://github.com/nfdi4cat/voc4cat/issues/new/choose) for you.
-- Create a fork of the voc4cat repository (if you don't yet have one) or pull the latest changes to your fork (via "Sync fork" button in GUI).
-- Create a feature branch for your contribution (via GitHub GUI or `git switch -c name-of-branch`)
-  - Add the xlsx file to the feature branch into the folder `inbox-excel-vocabs`
-  - The name of the file must match the vocabulary that you want to update. So do not change the filename, but keep `voc4cat.xlsx`.
-- Create a pull request with the updated Excel-file in this repository.
-  - Please describe your changes and the motivation for the changes in the pull request note or link to an issue with this information.
-    This will help reviewers to understand the proposed change and decide about it.
-- Your pull request will be processed automatically by a CI/CD pipeline that typically finishes in less than a minute.
-- Review the artifacts/logs generated by the CI pipeline.
-  - The [workflow artifact](https://docs.github.com/en/actions/managing-workflow-runs/downloading-workflow-artifacts) will contain an updated xlsx file that is recreated from the updated turtle-files.
-- If all is good your contribution will be either
-  - directly merged by the maintainers
-  - or a discussion will be started about what else is needed
-  - or why the proposed change may not fit.
-- If you need to fix something, first pull the changes made by the action with `git pull` (or "sync" in GUI) and then commit further changes to the pull request branch in your clone.
-  - If any commits have been made by the CI pipeline, pull the changes to your repo (via "Sync fork" button in GUI) before committing any additional changes.
-
-</details>
-
-Finally, when the proposed pull request is accepted, your changes will be integrated in the vocabularies in the folder `vocabularies`.
-The vocabularies are stored in split form using one folder per vocabulary.
-Each concept, collection and concept scheme is stored in a separate file using the ID-part of the IRI as file name.
-
-See [inbox-excel-vocabs/README.md](https://github.com/nfdi4cat/voc4cat/tree/main/inbox-excel-vocabs/README.md) for a minimal example how to test the submission process.
-
 ## How to suggest improvements to the tooling & template?
 
 To discuss about the workflow for maintaining SKOS vocabularies based on this template, create an [voc4cat-template issue](https://github.com/nfdi4cat/voc4cat-template/issues).