Add some test case elaborations for SSID_API_Manual_Test_Plans.md

doc/SSID_API_Manual_Test_Plans.md

@@ -27,6 +27,8 @@ curl -i \
  -F sizeOfNGram=5 \
  -F studentSubmissions=@cs1101_a1.zip
 ```
+Here, `cpp17` is an invalid value (but `cpp` is an allowed parameter).
+
 
 #### 3. {"error" : "Missing required parameter {parameterName}"}
 ```
@@ -37,6 +39,9 @@ curl -i \
  -F sizeOfNGram=5 \
  -F studentSubmissions=@cs1101_a1.zip
 ```
+Here, `title` parameter which is required is missing.
+
+
 
 #### 4. {"error" : "Parameter {parameterName} is invalid or not yet supported."}
 ```
@@ -50,6 +55,9 @@ curl -i \
  -F sensitivity=100
 ```
 
+Here, `sensitivity` is an invalid parameter not supported by SSID.
+
+
 #### 5. {"error" : "Missing or invalid API key."}
 ```
 curl -i \
@@ -174,4 +182,4 @@ curl -i \
 curl -i \
 -X GET "http://localhost:3000/api/v1/assignments/3018/submission_similarities/1549986/view_pdf" \
 -H "X-API-KEY: EVIL_API_KEY"
-```
+```