Adding diagrams for the OpenAPI generation process

```mermaid

graph TB

  classDef gitlab fill:#f90,stroke:#333,stroke-width:3px;

  classDef doc2oas fill:#00f,stroke:#333,stroke-width:3px;

  uploadDraftProcess["Generation of OpenAPI process"]

  uploadNewDraft["Upload Draft Word document to /doc folder of corresponding repository by the Rapporteur"]

  reviewMR{"Autogenerated Merge-Request review?"}

  applyMR["Apply the Merge-Request by the Rapporteur"]

  tag["Tag repository by the Rapporteur"]

  Fix{"Is a correction needed?"}

  Feedback["Feedback to Working Group"]

  support["Contact support (STF/CTI) to implement fixes"]

  class tag,reviewMR,uploadNewDraft,applyMR gitlab;

  class upload,syntax_validation,fixConfig doc2oas;

  uploadDraftProcess-->uploadNewDraft

  uploadNewDraft --> reviewMR

  reviewMR --Rejected-->Fix

  reviewMR --Approved-->applyMR

  Fix --doc2oas and/or config file-->support

  support-->uploadNewDraft

  Fix --Editorial spec fixes-->uploadNewDraft

  Fix --Major spec fixes-->Feedback

  applyMR --> tag 

  tag --> stop

```

```mermaid

graph TB

  classDef gitlab fill:#f90,stroke:#333,stroke-width:3px;

  classDef doc2oas fill:#00f,stroke:#333,stroke-width:3px;

  start("Start")

  draft["Draft specification stage"]

  upload["Generate the openapi from tools.etsi.org/doc2oas-ie"]

  syntax_validation["Automatic syntax validation"]

  isValidated{"Is syntax valid?"}

  isCompleted{"Is generated openapi completed?"}

  manualReview["Manual review for completeness"]

  fix["Feedback to Working Group"]

  fixConfig["Fix config file and upload"]

  isStableDraft{"Draft is stable?"}

  edithelpReview{"editHelp review completed?"}

  class tag,uploadNewDraft,reviewMR,applyMR gitlab;

  class upload,syntax_validation,fixConfig doc2oas;

  start-->draft

  draft-->upload

  upload-->syntax_validation

  syntax_validation --> isValidated

  isValidated--No-->fix

  isValidated--Yes-->manualReview

  fix --> draft

  manualReview --> isCompleted

  isCompleted --No--> fixConfig

  fixConfig --> upload

  isCompleted --Yes--> isStableDraft

  isStableDraft --Yes--> edithelpReview

  isStableDraft --No--> draft

  edithelpReview --No--> isStableDraft

  edithelpReview --Yes--> uploadDraftProcess

  uploadDraftProcess

```