Improve rst for lua-records

[jsoref]

Short description

Improve rst for lua-records

Checklist

I have:

• read the CONTRIBUTING.md document
• compiled this code
• tested this code
• included documentation (including possible behaviour changes)
• documented the code
• added or modified regression test(s)
• added or modified unit test(s)
• checked that this code was merged to master

[coveralls]

Pull Request Test Coverage Report for Build 8345244179

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 58 unchanged lines in 10 files lost coverage.
• Overall coverage decreased (-0.03%) to 59.227%

---

Files with Coverage Reduction	New Missed Lines	%
pdns/backends/gsql/gsqlbackend.hh	2	97.71%
pdns/axfr-retriever.cc	3	65.53%
pdns/opensslsigners.cc	3	61.13%
modules/gpgsqlbackend/spgsql.cc	3	67.94%
pdns/dnsdistdist/dnsdist.cc	4	68.09%
pdns/recursordist/test-syncres_cc1.cc	5	89.94%
modules/godbcbackend/sodbc.cc	6	70.8%
pdns/packethandler.cc	8	72.56%
pdns/dnsdistdist/dnsdist-tcp.cc	8	75.77%
modules/lmdbbackend/lmdbbackend.cc	16	72.5%

Totals
Change from base Build 8343656154:	-0.03%
Covered Lines:	113622
Relevant Lines:	158708

---

💛 - Coveralls