Fix missing code in the user profile (#29865)

fix #29820 
deleted by
https://github.com/go-gitea/gitea/pull/29248/files#diff-2b0b591787f16325539485e648a09ab6d3177f47dc129cfe84a35ffe141dfd19L39-L62,
which causing malfunction of follow/unfollow and missing description in
the user profile page.

routers/web/shared/user/header.go

 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/gitrepo"
 	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/markup"
+	"code.gitea.io/gitea/modules/markup/markdown"
 	"code.gitea.io/gitea/modules/optional"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/services/context"
 func PrepareContextForProfileBigAvatar(ctx *context.Context) {
 	prepareContextForCommonProfile(ctx)
 
+	ctx.Data["IsFollowing"] = ctx.Doer != nil && user_model.IsFollowing(ctx, ctx.Doer.ID, ctx.ContextUser.ID)
 	ctx.Data["ShowUserEmail"] = setting.UI.ShowUserEmail && ctx.ContextUser.Email != "" && ctx.IsSigned && !ctx.ContextUser.KeepEmailPrivate
 	if setting.Service.UserLocationMapURL != "" {
 		ctx.Data["ContextUserLocationMapURL"] = setting.Service.UserLocationMapURL + url.QueryEscape(ctx.ContextUser.Location)
 		return
 	}
 	ctx.Data["OpenIDs"] = openIDs
+	if len(ctx.ContextUser.Description) != 0 {
+		content, err := markdown.RenderString(&markup.RenderContext{
+			Metas: map[string]string{"mode": "document"},
+			Ctx:   ctx,
+		}, ctx.ContextUser.Description)
+		if err != nil {
+			ctx.ServerError("RenderString", err)
+			return
+		}
+		ctx.Data["RenderedDescription"] = content
+	}
 
 	showPrivate := ctx.IsSigned && (ctx.Doer.IsAdmin || ctx.Doer.ID == ctx.ContextUser.ID)
 	orgs, err := db.Find[organization.Organization](ctx, organization.FindOrgOptions{