README: Add migration guidance for breaking changes in v3.0.114 (pageIndex + CancellationToken)

[davidnmbond]

Problem

When upgrading from Cisco.Api 3.0.104 to 3.0.114, several API interface methods have breaking changes:

1. Added required pageIndex parameter to methods that previously didn't require one:

   • IEox.GetBySoftwareReleaseStringAsync(IEnumerable<string>) now requires int pageIndex (default: 1)
   • IEox.GetBySerialNumberAsync(string) now requires int pageIndex (default: 1)
   • ISoftwareSuggestion.GetByProductIdsAsync(IEnumerable<string>) now requires int pageIndex (default: 1)

2. Added required alias parameter to:

   • ISecurityAdvisory.GetAdvisoriesByOsTypeAndVersion(string type, string version) now requires string alias (default: "")

3. All obsolete overloads without CancellationToken are now errors (Obsolete(..., true)), requiring callers to pass a CancellationToken:

   • ISerialNumberToInfo.GetCoverageStatusBySerialNumbersAsync
   • ISerialNumberToInfo.GetCoverageSummaryBySerialNumbersAsync
   • IProductInfo.GetBySerialNumbersAsync
   • ISecurityAdvisory.GetOsVersionDataByType
   • ISecurityAdvisory.GetAdvisoriesByCveName
   • ISecurityAdvisory.GetAdvisoriesByProduct

Suggestion

Add a migration section to README.md (similar to what Uk.Parliament does) showing before/after examples for each breaking change. For example:

## Migration from 3.0.x to 3.0.114

### pageIndex parameter
Methods on `IEox` and `ISoftwareSuggestion` now require an explicit `pageIndex` parameter. Pass `1` for single-page requests:

```csharp
// Before
var result = await client.Eox.GetBySerialNumberAsync(serial);

// After
var result = await client.Eox.GetBySerialNumberAsync(serial, 1, cancellationToken);

CancellationToken now required

All overloads without CancellationToken are removed. Add cancellationToken (or default) as the last argument.

This would have saved significant time when upgrading MagicSuite from 3.0.104 to 3.0.114.