Add MegaLinter to adopters list

Author: nvuillam

ADOPTERS.md

@@ -10,6 +10,8 @@ Example entry:
 
 This is a list of adopters of using PowerShell Script Analyzer in production or in their products (in alphabetical order):
 
+* [MegaLinter](https://megalinter.io/), an open-source linters aggregator for CI, runs PSScriptAnalyzer out of the box to lint the PowerShell files of the repositories it analyzes
+  (see the [PSScriptAnalyzer page](https://megalinter.io/latest/descriptors/powershell_powershell/) in its documentation).
 * Microsoft Windows Build: PSScriptAnalyzer is automatically run against PowerShell scripts when performing a build for Windows to maintain and improve the quality of code as it gets checked in.
 * [PowerShellEditorServices](https://github.com/powershell/powershelleditorservices) uses PowerShell Script Analyzer to provide real-time
   linting of PowerShell scripts for editors such as [VSCode](https://code.visualstudio.com/), [Neovim](https://neovim.io/), [IntelliJ](https://www.jetbrains.com/idea/), and others.