Move Greek leader sequences to namespace

Convert Greek leader sequences to start with `e` - eg, `ea` for `alpha`.
The previous one letter sequences would overlap with other sequences,
which required waiting the entire leader term before being able to
continue input.

config/leader.dtsi

@@ -20,28 +20,28 @@ ZMK_LEADER_SEQUENCE(de_eszett,  &de_eszett,     LM2 LM2)  // ß
 
 /* Greek letters */
 
-ZMK_LEADER_SEQUENCE(el_alpha,   &el_alpha,      LM4)      // α
-ZMK_LEADER_SEQUENCE(el_beta,    &el_beta,       LT0)      // β
-ZMK_LEADER_SEQUENCE(el_gamma,   &el_gamma,      LM0)      // γ
-ZMK_LEADER_SEQUENCE(el_delta,   &el_delta,      LB1)      // δ
-ZMK_LEADER_SEQUENCE(el_epsilon, &el_epsilon,    RM2)      // ε
-ZMK_LEADER_SEQUENCE(el_zeta,    &el_zeta,       LB4)      // ζ
-ZMK_LEADER_SEQUENCE(el_eta,     &el_eta,        RB1)      // η
-ZMK_LEADER_SEQUENCE(el_theta,   &el_theta,      LB0)      // θ
-ZMK_LEADER_SEQUENCE(el_iota,    &el_iota,       RM3)      // ι
-ZMK_LEADER_SEQUENCE(el_kappa,   &el_kappa,      RB0)      // κ
-ZMK_LEADER_SEQUENCE(el_lambda,  &el_lambda,     RT1)      // λ
-ZMK_LEADER_SEQUENCE(el_mu,      &el_mu,         RM0)      // μ
-ZMK_LEADER_SEQUENCE(el_nu,      &el_nu,         RM1)      // ν
-ZMK_LEADER_SEQUENCE(el_xi,      &el_xi,         LB3)      // ξ
-ZMK_LEADER_SEQUENCE(el_omikron, &el_omikron,    RM4)      // ο
-ZMK_LEADER_SEQUENCE(el_pi,      &el_pi,         LT1)      // π
-ZMK_LEADER_SEQUENCE(el_rho,     &el_rho,        LM3)      // ρ
-ZMK_LEADER_SEQUENCE(el_sigma,   &el_sigma,      LM2)      // σ
-ZMK_LEADER_SEQUENCE(el_tau,     &el_tau,        LM1)      // τ
-ZMK_LEADER_SEQUENCE(el_upsilon, &el_upsilon,    RT2)      // υ
-ZMK_LEADER_SEQUENCE(el_phi,     &el_phi,        LT2)      // ϕ
-ZMK_LEADER_SEQUENCE(el_chi,     &el_chi,        LB2)      // χ
-ZMK_LEADER_SEQUENCE(el_psi,     &el_psi,        RT3)      // ψ
-ZMK_LEADER_SEQUENCE(el_omega,   &el_omega,      LT3)      // ω
+ZMK_LEADER_SEQUENCE(el_alpha,   &el_alpha,      RM2 LM4)  // α
+ZMK_LEADER_SEQUENCE(el_beta,    &el_beta,       RM2 LT0)  // β
+ZMK_LEADER_SEQUENCE(el_gamma,   &el_gamma,      RM2 LM0)  // γ
+ZMK_LEADER_SEQUENCE(el_delta,   &el_delta,      RM2 LB1)  // δ
+ZMK_LEADER_SEQUENCE(el_epsilon, &el_epsilon,    RM2 RM2)  // ε
+ZMK_LEADER_SEQUENCE(el_zeta,    &el_zeta,       RM2 LB4)  // ζ
+ZMK_LEADER_SEQUENCE(el_eta,     &el_eta,        RM2 RB1)  // η
+ZMK_LEADER_SEQUENCE(el_theta,   &el_theta,      RM2 LB0)  // θ
+ZMK_LEADER_SEQUENCE(el_iota,    &el_iota,       RM2 RM3)  // ι
+ZMK_LEADER_SEQUENCE(el_kappa,   &el_kappa,      RM2 RB0)  // κ
+ZMK_LEADER_SEQUENCE(el_lambda,  &el_lambda,     RM2 RT1)  // λ
+ZMK_LEADER_SEQUENCE(el_mu,      &el_mu,         RM2 RM0)  // μ
+ZMK_LEADER_SEQUENCE(el_nu,      &el_nu,         RM2 RM1)  // ν
+ZMK_LEADER_SEQUENCE(el_xi,      &el_xi,         RM2 LB3)  // ξ
+ZMK_LEADER_SEQUENCE(el_omikron, &el_omikron,    RM2 RM4)  // ο
+ZMK_LEADER_SEQUENCE(el_pi,      &el_pi,         RM2 LT1)  // π
+ZMK_LEADER_SEQUENCE(el_rho,     &el_rho,        RM2 LM3)  // ρ
+ZMK_LEADER_SEQUENCE(el_sigma,   &el_sigma,      RM2 LM2)  // σ
+ZMK_LEADER_SEQUENCE(el_tau,     &el_tau,        RM2 LM1)  // τ
+ZMK_LEADER_SEQUENCE(el_upsilon, &el_upsilon,    RM2 RT2)  // υ
+ZMK_LEADER_SEQUENCE(el_phi,     &el_phi,        RM2 LT2)  // ϕ
+ZMK_LEADER_SEQUENCE(el_chi,     &el_chi,        RM2 LB2)  // χ
+ZMK_LEADER_SEQUENCE(el_psi,     &el_psi,        RM2 RT3)  // ψ
+ZMK_LEADER_SEQUENCE(el_omega,   &el_omega,      RM2 LT3)  // ω