feat: add --experiments flag to replace --experimental (#5767)

- Deprecates the --experimental flag
- Adds a new flag --experiments which supports passing multiple comma-separated values or a wildcard value.
- Exposes a new endpoint /api/v2/experiments that returns the list of enabled experiments.
- Deprecates the field Features.Experimental in favour of this new API.
- Updates apidocgen to support type aliases (shoutout to @mtojek).
- Modifies apitypings to support generating slice types.
- Updates develop.sh to pass additional args after -- to $CODERD_SHIM.

codersdk/features.go

@@ -75,12 +75,14 @@ type Feature struct {
 }
 
 type Entitlements struct {
-	Features     map[FeatureName]Feature `json:"features"`
-	Warnings     []string                `json:"warnings"`
-	Errors       []string                `json:"errors"`
-	HasLicense   bool                    `json:"has_license"`
-	Experimental bool                    `json:"experimental"`
-	Trial        bool                    `json:"trial"`
+	Features   map[FeatureName]Feature `json:"features"`
+	Warnings   []string                `json:"warnings"`
+	Errors     []string                `json:"errors"`
+	HasLicense bool                    `json:"has_license"`
+	Trial      bool                    `json:"trial"`
+
+	// DEPRECATED: use Experiments instead.
+	Experimental bool `json:"experimental"`
 }
 
 func (c *Client) Entitlements(ctx context.Context) (Entitlements, error) {