fix a few grammatical issues in the readme

[axellse]

Description

This fixes a few grammatical issues in the readme to give the project a more proffesional feel.

Heres why i chose to make the changes i made:

• Line 5 (has to had): Present to past tense.
• Line 9 (will happens to happen): in swedish you can say "kommer hända" here but in english you would drop the "will". Happens have also been changed to happen.
• Line 13 (with the first mingle event start! to the first mingle event will start!): "with" translates to "med", so that sentence would be translated to "med den första mingel eventet börja". I changed to "with" to "will" and also moved the "will" due to english sentence structure being a bit different than swedish.
• Line 14 (drop at): in swedish "at" and "on" both translates to "på", but here you would say "on" instead of "at", but it isn't needed so i decided to drop it altogether.
• Line 14-15 (be part to take part): be part= vara del i , take part in = ta del i.
• Line 17 (uses to use): "uses" is third person singular.
• Line 17: (be part to take part): be part= vara del i , take part in = ta del i.
• Line 19 (will happen to happend): since "looked" is past tense you also have to keep that up in the rest of the sentence
• Line 21 (include "who"): its sounds a bit odd without the "who"
• Line 26 (was to were): its always were if "you" comes before.
• Line 28 (suggests to suggest): With verbs, only those with a third-person singular noun or pronoun as a subject add an s to the end.
• Line 30 (has to have): since there are 2 more events, you would use have since thats for plural.

Checklist:

• [✅ ] I confirm that I wrote and/or have the right to submit the contents of my PR, by agreeing to the Developer Certificate of Origin (see https://github.com/svt/open-source-project-template/blob/master/docs/CONTRIBUTING.adoc[docs/CONTRIBUTING]).
• [✅] PR has an informative and human-readable title
• [✅] Changes are limited to a single goal (no scope creep)
• [✅] Code can be automatically merged (no conflicts)

[nsg]

Awesome! Thank you for the fantastic description 👍