documentation(EJ2-1015792): Added content for spreadsheet architecture overview.

[DinakarManickam4212]

UG-1015792: Include a Section on Spreadsheet Architecture in the Spreadsheet Documentation.

[SyncfusionBuild]

Build Status: INPROGRESS 🔃
Build Location: EJ2-1015792-dev

[SyncfusionBuild]

The running CI Job is terminated due to changes committed on the source branch for this Merge Request and CI triggered for latest commit.

[SyncfusionBuild]

CI Status: ABORTED ❌
Source Compilation: FAILURE ❌
Build Location: EJ2-1015792-dev

[SyncfusionBuild]

Build Status: INPROGRESS 🔃
Build Location: EJ2-1015792-dev

[SyncfusionBuild]

CI Status: FAILURE ❌
Source Compilation: SUCCESS ✅
Failure Reason: CI Failure with violation
Build Location: EJ2-1015792-dev
Technical Error(s): 0
Spelling Error(s): 1
Image Alt Text Error(s): 0
Image Size Error(s): 0
Image Name Error(s): 0
Front matter Error(s): 0
File Path Error(s): 0
CodeSnippet File Path Missing Error(s): 0
Toc Anchor Tags Validation Error(s): 0
MD Tag Validation Error(s): 0

[SyncfusionBuild]

Build Status: INPROGRESS 🔃
Build Location: EJ2-1015792-dev

[SyncfusionBuild]

CI Status: SUCCESS ✅
Source Compilation: SUCCESS ✅
Build Location: EJ2-1015792-dev
Technical Error(s): 0
Spelling Error(s): 0
Image Alt Text Error(s): 0
Image Size Error(s): 0
Image Name Error(s): 0
Front matter Error(s): 0
File Path Error(s): 0
CodeSnippet File Path Missing Error(s): 0
Toc Anchor Tags Validation Error(s): 0
MD Tag Validation Error(s): 0