minor doc fixes

go/cmd/dolt/commands/gc.go

@@ -36,7 +36,9 @@ var gcDocs = cli.CommandDocumentationContent{
 	ShortDesc: "Cleans up unreferenced data from the repository.",
 	LongDesc: `Searches the repository for data that is no longer referenced and no longer needed.
 
-If the {{.EmphasisLeft}}--shallow{{.EmphasisRight}} flag is supplied, a faster but less thorough garbage collection will be performed.`,
+If the {{.EmphasisLeft}}--shallow{{.EmphasisRight}} flag is supplied, a faster but less thorough garbage collection will be performed.
+
+{{.EmphasisLeft}}dolt gc{{.EmphasisRight}} won't work if there is a running server. Use {{.EmphasisLeft}}dolt sql -q 'call dolt_gc()'{{.EmphasisRight}} instead.`,
 	Synopsis: []string{
 		"[--shallow]",
 	},

go/cmd/dolt/commands/ls.go

@@ -32,7 +32,7 @@ import (
 
 var lsDocs = cli.CommandDocumentationContent{
 	ShortDesc: "List tables",
-	LongDesc: `With no arguments lists the tables in the current working set but if a commit is specified it will list the tables in that commit.  If the {{.EmphasisLeft}}--verbose{{.EmphasisRight}} flag is provided a row count and a hash of the table will also be displayed.
+	LongDesc: `With no arguments lists the tables in the current working set but if a commit is specified it will list the tables in that commit.  If the {{.EmphasisLeft}}--verbose{{.EmphasisRight}} flag is provided a row count of the table will also be displayed.
 
 If the {{.EmphasisLeft}}--system{{.EmphasisRight}} flag is supplied this will show the dolt system tables which are queryable with SQL.
 

go/cmd/dolt/commands/query_diff.go

@@ -55,7 +55,7 @@ func (q QueryDiff) Name() string {
 }
 
 func (q QueryDiff) Description() string {
-	return "description"
+	return "Shows table diff between two queries."
 }
 
 func (q QueryDiff) Docs() *cli.CommandDocumentation {