Remove some formatting inconsistencies

I've tried automatically parsing the docs, and these inconsistencies made it harder to do that.

(I tried to do that for a project which I can't share yet, I'm not sure if it'll even work).

doc/lightning-connect.7.md

@@ -4,7 +4,7 @@ lightning-connect -- Command for connecting to another lightning node
 SYNOPSIS
 --------
 
-**connect** *id* \[*host* *port*\]
+**connect** *id* \[*host*\] \[*port*\]
 
 DESCRIPTION
 -----------

doc/lightning-datastore.7.md

@@ -4,7 +4,7 @@ lightning-datastore -- Command for storing (plugin) data
 SYNOPSIS
 --------
 
-**datastore** *key* [*string*] [*hex*] [*mode*] [*generation*]
+**datastore** *key* \[*string*\] \[*hex*\] \[*mode*\] \[*generation*\]
 
 DESCRIPTION
 -----------

doc/lightning-deldatastore.7.md

@@ -4,7 +4,7 @@ lightning-deldatastore -- Command for removing (plugin) data
 SYNOPSIS
 --------
 
-**deldatastore** *key* [*generation*]
+**deldatastore** *key* \[*generation*\]
 
 DESCRIPTION
 -----------

doc/lightning-listconfigs.7.md

@@ -4,7 +4,7 @@ lightning-listconfigs -- Command to list all configuration options.
 SYNOPSIS
 --------
 
-**listconfigs** \[config\]
+**listconfigs** \[*config*\]
 
 DESCRIPTION
 -----------

doc/lightning-listdatastore.7.md

@@ -4,7 +4,7 @@ lightning-listdatastore -- Command for listing (plugin) data
 SYNOPSIS
 --------
 
-**listdatastore** [*key*]
+**listdatastore** \[*key*\]
 
 DESCRIPTION
 -----------

doc/lightning-listnodes.7.md

@@ -4,7 +4,7 @@ lightning-listnodes -- Command to get the list of nodes in the known network.
 SYNOPSIS
 --------
 
-**listnodes** \[id\]
+**listnodes** \[*id*\]
 
 DESCRIPTION
 -----------

doc/lightning-listpays.7.md

@@ -4,7 +4,7 @@ lightning-listpays -- Command for querying payment status
 SYNOPSIS
 --------
 
-**listpays** \[bolt11\] \[payment_hash\] \[status\]
+**listpays** \[*bolt11*\] \[*payment_hash*\] \[*status*\]
 
 DESCRIPTION
 -----------

doc/lightning-ping.7.md

@@ -4,7 +4,7 @@ lightning-ping -- Command to check if a node is up.
 SYNOPSIS
 --------
 
-**ping** *id* \[len\] \[pongbytes\]
+**ping** *id* \[*len*\] \[*pongbytes*\]
 
 DESCRIPTION
 -----------

doc/lightning-plugin.7.md

@@ -4,7 +4,7 @@ lightning-plugin -- Manage plugins with RPC
 SYNOPSIS
 --------
 
-**plugin** command \[parameter\] \[second\_parameter\]
+**plugin** command \[*parameter*\] \[*second\_parameter*\]
 
 DESCRIPTION
 -----------

doc/lightning-reserveinputs.7.md

@@ -4,7 +4,7 @@ lightning-reserveinputs -- Construct a transaction and reserve the UTXOs it spen
 SYNOPSIS
 --------
 
-**reserveinputs** *psbt* [*exclusive*] [*reserve*]
+**reserveinputs** *psbt* \[*exclusive*\] \[*reserve*\]
 
 DESCRIPTION
 -----------

doc/lightning-sendpsbt.7.md

@@ -4,7 +4,7 @@ lightning-sendpsbt -- Command to finalize, extract and send a partially signed b
 SYNOPSIS
 --------
 
-**sendpsbt** *psbt* [*reserve*]
+**sendpsbt** *psbt* \[*reserve*\]
 
 DESCRIPTION
 -----------

doc/lightning-signpsbt.7.md

@@ -4,7 +4,7 @@ lightning-signpsbt -- Command to sign a wallet's inputs on a provided bitcoin tr
 SYNOPSIS
 --------
 
-**signpsbt** *psbt* [*signonly*]
+**signpsbt** *psbt* \[*signonly*\]
 
 DESCRIPTION
 -----------

doc/lightning-unreserveinputs.7.md

@@ -4,7 +4,7 @@ lightning-unreserveinputs -- Release reserved UTXOs
 SYNOPSIS
 --------
 
-**unreserveinputs** *psbt* [*reserve*]
+**unreserveinputs** *psbt* \[*reserve*\]
 
 DESCRIPTION
 -----------