Move slack invite link to head page

Author: mfherbst

index.md

@@ -9,7 +9,6 @@ We're currently working on setting up this website.
 
 \toc
 
-
 ## Projects
 Feel free to have a look at some of our projects:
 - [DFTK.jl](https://dftk.org): A flexible code for density-functional theory simulations
@@ -21,5 +20,9 @@ Feel free to have a look at some of our projects:
 - [ACE.jl](https://github.com/ACEsuit/ACE.jl): Atomic cluster expansion in Julia
 - [asedftk](https://github.com/mfherbst/asedftk): DFTK-compatible calculator interface for the Atomic Simulation Environment (ASE).
 
+## Slack channel
+[slack-url]: https://join.slack.com/t/juliamolsim/shared_invite/zt-tc060co0-HgiKApazzsQzBHDlQ58A7g
+Get involved in ongoing conversations by joining our [Slack workspace][slack-url]!
+
 ## Topics
 - [Quantum chemistry folks in Julia](/qchem/)

qchem.md

@@ -8,9 +8,6 @@ date = Date(2021, 7, 14)
 
 \toc
 
-## Slack channel
-Get involved in ongoing conversations on [our Slack workspace](https://join.slack.com/t/juliamolsim/shared_invite/zt-tc060co0-HgiKApazzsQzBHDlQ58A7g)!
-
 ## Meetings
 The "kickoff" will be [the BoF session](https://pretalx.com/juliacon2021/talk/ZQJAW3/)
 at 2021 JuliaCon.