docs: expand short frontmatter descriptions for SEO

docs/api-reference/organization/remove-org-member.mdx

@@ -1,5 +1,5 @@
 ---
 title: "Remove Organization Member"
-description: "Remove a member from an organization"
+description: "Remove a member from a Mem0 organization by revoking their access and clearing their assigned role."
 openapi: "delete /api/v1/orgs/organizations/{org_id}/members/"
 ---

docs/api-reference/organization/update-org-member.mdx

@@ -1,5 +1,5 @@
 ---
 title: "Update Organization Member"
-description: "Update organization member role"
+description: "Update the role assigned to an existing member of a Mem0 organization to change their permissions."
 openapi: "put /api/v1/orgs/organizations/{org_id}/members/"
 ---