chore: added LGTM badges to readme (fixes #1380) (#1501)

Author: XDRAGON2002

.github/actions/spelling/allow.txt

@@ -164,6 +164,7 @@ kexectools
 kritirikhi
 landley
 lgpl
+lgtm
 libarchive
 libbluetooth
 libbpg

README.md

@@ -8,6 +8,7 @@
 [![Code style: black](https://img.shields.io/badge/code%20style-black-000000.svg)](https://github.com/python/black)
 [![Imports: isort](https://img.shields.io/badge/%20imports-isort-%231674b1?style=flat&labelColor=ef8336)](https://pycqa.github.io/isort/)
 [![CII Best Practices](https://bestpractices.coreinfrastructure.org/projects/5380/badge)](https://bestpractices.coreinfrastructure.org/projects/5380)
+[![Language grade: Python](https://img.shields.io/lgtm/grade/python/g/intel/cve-bin-tool.svg?logo=lgtm&logoWidth=18)](https://lgtm.com/projects/g/intel/cve-bin-tool/context:python)
 
 The CVE Binary Tool is a free, open source tool to help you find known vulnerabilities in software, using data from the [National Vulnerability Database](https://nvd.nist.gov/) (NVD) list of [Common Vulnerabilities and Exposures](https://en.wikipedia.org/wiki/Common_Vulnerabilities_and_Exposures#:~:text=Common%20Vulnerabilities%20and%20Exposures%20(CVE)%20is%20a%20dictionary%20of%20common,publicly%20known%20information%20security%20vulnerabilities.) (CVEs).