fix development setup instructions in CONTRIBUTING.md

[marcel2012]

Description

Please include a summary of the changes and the related issue. Please also include relevant motivation and context. List any dependencies that are required for this change.

This change fix issues during development setup:

[Kubero] 42085  - 09/14/2026, 1:09:06 AM   DEBUG [DatabaseService] Running Prisma migrations...
node:fs:779
  return binding.open(
                 ^

Error: ENOENT: no such file or directory, open './kubeconfig'
    at Object.openSync (node:fs:779:18)
    at Object.readFileSync (node:fs:625:35)
    at KubeConfig.loadFromFile (/home/test/kub/server/node_modules/@kubernetes/client-node/dist/config.js:87:32)
    at KubernetesService.initKubeConfig (/home/test/kub/server/src/kubernetes/kubernetes.service.ts:79:15)
    at new KubernetesService (/home/test/kub/server/src/kubernetes/kubernetes.service.ts:65:10)
    at Injector.instantiateClass (/home/test/kub/server/node_modules/@nestjs/core/injector/injector.js:418:19)
    at callback (/home/test/kub/server/node_modules/@nestjs/core/injector/injector.js:70:45)
    at async Injector.resolveConstructorParams (/home/test/kub/server/node_modules/@nestjs/core/injector/injector.js:170:24)
    at async Injector.loadInstance (/home/test/kub/server/node_modules/@nestjs/core/injector/injector.js:75:13)
    at async Injector.loadProvider (/home/test/kub/server/node_modules/@nestjs/core/injector/injector.js:103:9) {
  errno: -2,
  code: 'ENOENT',
  syscall: 'open',
  path: './kubeconfig'
}

[Kubero] 42265  - 09/14/2026, 1:09:58 AM   ERROR [DatabaseService] Prisma migration failed
[Kubero] 42265  - 09/14/2026, 1:09:58 AM   ERROR [DatabaseService] PrismaClientInitializationError: 
Invalid `prisma.$executeRawUnsafe()` invocation:


Error querying the database: Error code 14: Unable to open the database file
    at ei.handleRequestError (/home/test/kub/server/node_modules/@prisma/client/src/runtime/RequestHandler.ts:242:13)
    at ei.handleAndLogRequestError (/home/test/kub/server/node_modules/@prisma/client/src/runtime/RequestHandler.ts:174:12)
    at ei.request (/home/test/kub/server/node_modules/@prisma/client/src/runtime/RequestHandler.ts:143:12)
    at async a (/home/test/kub/server/node_modules/@prisma/client/src/runtime/getPrismaClient.ts:833:24)
    at async DatabaseService.RunMigrations (/home/test/kub/server/src/database/database.service.ts:61:7)
    at async DatabaseService.DBinit (/home/test/kub/server/src/database/database.service.ts:29:5)
    at async bootstrap (/home/test/kub/server/src/main.ts:33:3) {
  clientVersion: '6.16.1',
  errorCode: undefined,
  retryable: undefined
}

yarn run v1.22.22
error Command "watch" not found.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

Type of change

Please delete options that are not relevant.

• Template (non-breaking change which adds a template)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• Development server started

Test Configuration:

• Operator Version:
• Kubernetes Version:
• Kubero CLI Version (if applicable):

Checklist:

• I removed unnecessary debug logs
• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I documented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings