add details for endpoints table

cubesat_mission/README.md

@@ -77,6 +77,9 @@ As the budget link depends on many factors(types of antenna on the ground, point
 
 The Thingsat board transmits LoRaWAN-compliant frames using the following parameters and credentials
 
+<details>
+<summary>Endpoints table</summary>
+
 | Type     | Network   | DevAddr      | Codec           | Area | Key                                        |
 | -------- | --------- | ------------ | --------------- | ---------- |----------------------------------------------- |
 | `Beacon`  | CampusIoT |              | Beacon (inver IQ) | France, Svalbard, French Polynesia | Not relevant |
@@ -90,6 +93,7 @@ The Thingsat board transmits LoRaWAN-compliant frames using the following parame
 | `DTUP`    | [Objenious Spot](https://spot.objenious.com/)    | `0eb536bd`  | All | France (eu868) | AES AppSKey: `954740cb3165e12c970b4aeada5eddd8` |
 | `DTUP`    | [Helium](https://explorer.helium.com/)    | `48000007`  | All | World (eu868 regions)  | AES AppSKey: `869A9F323B21370EEB38EC06D64F09DC` |
 
+</details>
 
 The CSV files of the endpoints is [here](./messages/endpoints.pub.csv).