Fix docs and docstrings

[ohno]

• Add quick start section to README.md (refer to https://github.com/ohno/MyPkg65.jl and relpalce Installation to Quick Start).
• Replace [STO-3G](https://juliafewbody.github.io/TwoBody.jl/dev/Rayleigh-Ritz/#STO-3G) to Example of STO-3G in Rayleigh-Ritz.md.
• Fix the note in https://juliafewbody.github.io/TwoBody.jl/dev/Rayleigh-Ritz/#TwoBody.matrix-Tuple{Operator,%20BasisSet}-Rayleigh-Ritz.
• Add The numerical solution agrees well with the analytical solution even in the excited state. to https://juliafewbody.github.io/TwoBody.jl/dev/Rayleigh-Ritz/#Example-of-Hydrogen-Atom and https://juliafewbody.github.io/TwoBody.jl/dev/Rayleigh-Ritz/#Example-of-Spherical-Oscillator.
• Remove You can also generate a complement from one basis function: and the code in https://juliafewbody.github.io/TwoBody.jl/dev/Free-Complement/#Example-of-Hydrogen-Atom (duplication).
• Change the basis set in Usage of GEM (replace BS = GeometricBasisSet(GaussianBasis, 0.1, 10.0, 20) with the 4 basis functions like as RR).
• Relpace Standard model with "Usage" in VNN.
• Replace J. M. Thijssen, [Computational Physics, 2nd ed.](https://doi.org/10.1017/CBO9781139171397), Cambridge University Press (2007); 邦訳: 松田和典, 道廣嘉隆, 谷村吉隆, 高須昌子, 吉江友照 訳, 『計算物理学』, 丸善出版 (2012). with the English version in VMC.
• Add GEM to the diagram of Architecture.