DOC-308: Documentation for conf file

docs/prover/cli/conf-file-api.md

@@ -0,0 +1,102 @@
+Certora Prover Conf File API
+============================
+
+The **Conf File API** is an alternative API for  `certoraRun` . In terms of functionality 
+this API is identical to the [CLI Options](options.md) API. Instead of calling `certoraRun` 
+with a list of shell flags, some or all the flags can be stored in a [JSON](https://www.json.org/json-en.html) file 
+(to be more precise the format is [JSON5](https://json5.org/)):
+
+```
+certoraRun my_params.conf
+```
+
+Conf files must use the <strong>.conf</strong> suffix
+
+
+How CLI Options are mapped to JSON
+----------------------------------
+
+**JSON Keys**
+
+JSON keys in the conf file are the CLI option flag names without the leading dashes.
+For example, 
+the CLI flag **--verify** will be stored under the **"verify"** in the conf file
+
+The JSON key for the input files in the CLI API is **"files"**
+
+**String Value CLI Options**
+
+Flags in CLI API that accept a single string will be stored as **JSON Strings**. Example:
+```
+"solc": "solc4.25"
+```
+**Number Value CLI Options**
+
+Flags in CLI API that accept numbers will be stored as **JSON Strings** not as **JSON Numbers**. Example:
+
+```
+"smt_timeout": "600"
+```
+
+**Boolean Value CLI Options**
+
+Since boolean flags in the CLI API do not get a value they will be stored as **JSON true**. Example:
+
+```
+"send_only": true
+```
+**List Value CLI Options**
+
+Flags in CLI API that accept multiple strings will be stored as **JSON Arrays**. Example:
+```
+    "packages": [
+        "@balancer-labs/v2-solidity-utils=pkg/solidity-utils",
+        "@balancer-labs/v2-vault=pkg/vault"
+    ]
+```
+
+**Map Value CLI Options**
+
+Flags in CLI API that are maps will be stored as **JSON Objects**. Example:
+```
+    "solc_map": {
+        "A": "solc5.11",
+        "B": "solc5.9",
+        "C": "solc6.8"
+    }
+
+```
+
+A conf file is generated each time `certoraRun` completes execution successfully.
+The conf file is stored as `**run.conf**` in the build directory under **`.certora_internal`**.
+<p>Conf file of the latest run can be found in:
+
+```
+./.certora_internal/latest/run.conf
+```
+
+
+**Complete Example**
+
+The command line:
+```
+certoraRun SolcArgs/A.sol SolcArgs/A.sol:B SolcArgs/C.sol --verify A:SolcArgs/Trigger.spec --solc_map SolcArgs/A.sol=solc6.1,B=solc6.1,C=solc5.12 --multi_assert_check 
+```
+
+will generate the conf file below:
+```
+{
+    "files": [
+        "SolcArgs/A.sol",
+        "SolcArgs/A.sol:B",
+        "SolcArgs/C.sol"
+    ],
+    "multi_assert_check": true,
+    "solc_map": {
+        "B": "solc6.1",
+        "C": "solc5.12",
+        "SolcArgs/A.sol": "solc6.1"
+    },
+    "verify": "A:SolcArgs/Trigger.spec"
+}
+```

docs/prover/cli/index.md

@@ -8,5 +8,6 @@ Certora Prover CLI
 verification.md
 linking.md
 options.md
+conf-file-api.md
 ```