Add Pebble storage backend documentation for the Execution Layer

[ParthSinghPS]

This PR adds a concise documentation section describing Pebble as a storage
backend used by some Ethereum execution clients.

The section focuses on:

• Pebble’s role as a replacement for LevelDB in the Execution Layer
• The key advantages Pebble provides over LevelDB for execution workloads
• How Pebble fits the abstract storage model defined by the Execution Layer
  Specification

The intent is to provide clear, non-redundant context for readers progressing
from the LevelDB section, without introducing implementation-specific or
protocol-level assumptions.

[github-actions]

Hi @ParthSinghPS,

⚠️ Potential typos found in your pull request:

• 📄 ./docs/eps/week1.md (line(s) 134):
  1. ❌ resleased
• 📄 ./docs/eps/schedule.md (line(s) 35):
  1. ❌ Rakita
• 📄 ./docs/wiki/testing/consensus-spec-tests.md (line(s) 15):
  1. ❌ symlinks
• 📄 ./docs/wiki/testing/consensus-spec-tests.md (line(s) 23):
  1. ❌ incorect
• 📄 ./docs/wiki/pectra-faq.md (line(s) 3,5,6,9,15,17,19,29,57,83,99,110,186):
  1. ❌ ectra
• 📄 ./docs/wiki/pectra-faq.md (line(s) 59,63,65,121,150,152,186,197,199):
  1. ❌ sys
• 📄 ./docs/wiki/pectra-faq.md (line(s) 152,199):
  1. ❌ asm
• 📄 ./docs/wiki/pectra-faq.md (line(s) 51,114,140,152,199,237,241):
  1. ❌ eas
• 📄 ./docs/wiki/pectra-faq.md (line(s) 59,63,65,121,150,152,186,197,199):
  1. ❌ sys
• 📄 ./docs/wiki/pectra-faq.md (line(s) 152,199):
  1. ❌ asm
• 📄 ./docs/wiki/pectra-faq.md (line(s) 51,114,140,152,199,237,241):
  1. ❌ eas
• 📄 ./docs/wiki/CL/cl-networking.md (line(s) 13):
  1. ❌ orginally
• 📄 ./docs/wiki/CL/cl-networking.md (line(s) 29):
  1. ❌ multiaddress
• 📄 ./docs/wiki/CL/cl-networking.md (line(s) 31):
  1. ❌ Multiaddress
• 📄 ./docs/wiki/CL/cl-networking.md (line(s) 31):
  1. ❌ Multiaddress
• 📄 ./docs/wiki/CL/cl-networking.md (line(s) 66):
  1. ❌ negociation
• 📄 ./docs/wiki/CL/cl-networking.md (line(s) 75):
  1. ❌ Multiaddrs
• 📄 ./docs/wiki/CL/cl-networking.md (line(s) 80):
  1. ❌ proactivily
• 📄 ./docs/wiki/CL/cl-networking.md (line(s) 56,82,128,279):
  1. ❌ kad
• 📄 ./docs/wiki/CL/cl-networking.md (line(s) 91):
  1. ❌ multihashes
• 📄 ./docs/wiki/CL/cl-networking.md (line(s) 91,97,281):
  1. ❌ multihash
• 📄 ./docs/wiki/CL/cl-networking.md (line(s) 101):
  1. ❌ Multihash
• 📄 ./docs/wiki/CL/cl-networking.md (line(s) 107):
  1. ❌ multibase
• 📄 ./docs/wiki/CL/cl-networking.md (line(s) 109):
  1. ❌ establised
• 📄 ./docs/wiki/CL/cl-networking.md (line(s) 126):
  1. ❌ Multicast
• 📄 ./docs/wiki/CL/cl-networking.md (line(s) 128,131):
  1. ❌ multiaddrs
• 📄 ./docs/wiki/CL/cl-networking.md (line(s) 128,131):
  1. ❌ multiaddrs
• 📄 ./docs/wiki/CL/cl-networking.md (line(s) 149):
  1. ❌ mututal
• 📄 ./docs/wiki/CL/cl-networking.md (line(s) 159):
  1. ❌ rount
• 📄 ./docs/wiki/CL/cl-networking.md (line(s) 163):
  1. ❌ Gossibhub
• 📄 ./docs/wiki/CL/cl-networking.md (line(s) 160,171):
  1. ❌ gossibsub
• 📄 ./docs/wiki/EL/el-specs.md (line(s) 747):
  1. ❌ OOG
• 📄 ./docs/wiki/EL/el-specs.md (line(s) 767):
  1. ❌ bn
• 📄 ./docs/wiki/EL/el-architecture.md (line(s) 321):
  1. ❌ memtables

ℹ️ How to fix this error:

1. If these are actual typos:

   • Open the files at the specified line numbers and fix them

2. If these are names or one-off nouns:

   • Wrap them in <name> tags
   • Example: <name>Alex Pereira</name>
   • Use this for people's names or unique terms that appear rarely

3. If these are valid terms:

   • Add them to wordlist.txt (one word per line)
   • Terms must be plain text without spaces/special chars
   • The list is case-insensitive

4. If these are code terms:

   • Wrap them in backticks (`) in your markdown

ℹ️ Checking for typos locally

1. Install aspell for your platform
2. Navigate to project root and run:

for f in **/*.md ; do echo $f ; aspell --lang=en_US --mode=markdown --home-dir=. --personal=wordlist.txt --ignore-case=true --camel-case --add-sgml-skip nospellcheck list < $f | sort | uniq -c ; done

Learn more about wordlist format